Output listing of installation command: sh ./install.sh as root:
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root@lndserver:~/Downloads/AirVPN/AirVPN-Suite-x86_64-2.0.0/AirVPN-Suite# sh ./install.sh

AirVPN suite installation script

Do you want to install AirVPN Suite? [y/n] y

System is using systemd

D-Bus directory is /etc/dbus-1/system.d

Installing bluetit to /sbin
Installing goldcrest to /usr/local/bin
Installing hummingbird to /usr/local/bin
Installing cuckoo to /usr/local/bin
Installing airsu to /usr/local/bin
Installing bluetit configuration files
Installing D-Bus configuration files
Installing systemd bluetit.service units

Do you want to enable bluetit.service units? [y/n] y
Created symlink /etc/systemd/system/multi-user.target.wants/bluetit.service → /etc/systemd/system/bluetit.service.
Bluetit service enabled
Created symlink /etc/systemd/system/suspend.target.wants/bluetit-suspend.service → /etc/systemd/system/bluetit-suspend.service.
Created symlink /etc/systemd/system/suspend-then-hibernate.target.wants/bluetit-suspend.service → /etc/systemd/system/bluetit-suspend.service.
Created symlink /etc/systemd/system/hibernate.target.wants/bluetit-suspend.service → /etc/systemd/system/bluetit-suspend.service.
Created symlink /etc/systemd/system/hybrid-sleep.target.wants/bluetit-suspend.service → /etc/systemd/system/bluetit-suspend.service.
Created symlink /etc/systemd/system/sleep.target.wants/bluetit-suspend.service → /etc/systemd/system/bluetit-suspend.service.
Bluetit-suspend service enabled
Created symlink /etc/systemd/system/suspend.target.wants/bluetit-resume.service → /etc/systemd/system/bluetit-resume.service.
Created symlink /etc/systemd/system/suspend-then-hibernate.target.wants/bluetit-resume.service → /etc/systemd/system/bluetit-resume.service.
Created symlink /etc/systemd/system/hibernate.target.wants/bluetit-resume.service → /etc/systemd/system/bluetit-resume.service.
Created symlink /etc/systemd/system/hybrid-sleep.target.wants/bluetit-resume.service → /etc/systemd/system/bluetit-resume.service.
Created symlink /etc/systemd/system/sleep.target.wants/bluetit-resume.service → /etc/systemd/system/bluetit-resume.service.
Bluetit-resume service enabled

Do you want to start Bluetit service now? [y/n] y
Job for bluetit.service failed because the control process exited with error code.
See "systemctl status bluetit.service" and "journalctl -xeu bluetit.service" for details.
Cannot start Bluetit service
Run 'systemctl status bluetit.service' for more information
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NOTE: As shown above, bluetit.service failed, and the reason is that /sbin/bluetit doesn't have the right permissions:
I issued the following command to check this:
ls -l /sbin/bluetit, with the following result: -rw-r--r-- 1 root root 5644424 Jan  7 11:21 /sbin/bluetit

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See hereunder the complete bluetit.rc w/o login credentials, which I modified as follows:
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#
# bluetit runcontrol file
#

# AirVPN bootstrap servers

bootserver                  https://airvpn.org
bootserver                  https://www.airvpn.org
bootserver                  https://ipv6.airvpn.org
bootserver                  https://ipv4.airvpn.org

# RSA Parameters

rsaexponent               AQAB
rsamodulus                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

# bootserver                        <ip|url>
# rsaexponent                       <value>
# rsamodulus                        <value>
airconnectatboot                    quick
networklockpersist                  iptables
airvpntype                          wireguard
airusername                         <my_login_username>
airpassword                         <my_passwd>
# airkey                            <airvpn_user_key>
# airserver                         <airvpn_server_name>
# aircountry                        <airvpn_country_name>
# airproto                          <udp|tcp>
# airport                           <port>
# aircipher                         <cipher_name>
airipv6                             no
# air6to4                           <yes|no>
manifestupdateinterval              15
# airwhiteserverlist                <server list>
# airblackserverlist                <server list>
# airwhitecountrylist               <country list>
# airblackcountrylist               <country list>
forbidquickhomecountry              yes
# allowuservpnprofiles              <yes|no>
allowtrafficsplitting               yes
trafficsplitnamespace               aircuckoo
trafficsplitinterface               wlp2s0
trafficsplitnamespaceinterface      airwlp2s0
trafficsplitipv4                    auto
trafficsplitipv6                    auto
trafficsplitfirewall                yes
# country                           <ISO code>
# remote                            <ip|url list>
proto                               udp
port                                443
# mtu                               <value>
# tunpersist                        <yes|no>
cipher                              chacha20-poly1305
# maxconnretries                    <number>
# tcpqueuelimit                     <value>
# ncpdisable                        <yes|no>
networklock                         on
networkcheck                        airvpn
allowprivatenetwork                 yes
allowping                           output
allowipv6ndp                        yes
# ignorednspush                     <yes|no>
# timeout                           <seconds>
# compress                          <yes|no|asym>
# tlsversionmin                     <disabled|default|tls_1_x>
# proxyhost                         <ip|url>
# proxyport                         <port>
# proxyusername                     <username>
# proxypassword                     <password>
# proxybasic                        <yes|no>
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