Jitsi meet plugin on moodle3.9: blank page when starting a session

hello all,

i have moodle 3.9 , i installed on it jitsi meet videoconference plugin.

server: debian10 ,

the plugin was installed without errors, on configuration i left all fields to their default values even the domain is left to meet.jit.si.

when i try to use the plugin in a course, it shows in blank page as if there was no thing happened.
what can be the problem and how to fix it?

You may ask directly to plugin developers