Jigasi after install not working

Hello, I already tried several times to install jigasi with jitsi running on ubutnu 18.04. According to install instructions service jitsi-videobridge2 restart caused
Failed to restart jitsi-videobridge2.service: Unit jitsi-videobridge2.service not found

In jitsi runnung the “+” sign appears and the invitation requester can be filled. However, neither the own phone number appears when clicking the + sign nor a message or a signal sound appears on the phone number invited. The logfile is enclosed. Thank you for your advice in advance.
jigasi.log (135.9 KB)