I clicked on the goeuropean.org database and was surprised that no alternative to Zoom was listed.

https://meet.ffmuc.net/ There is ffmeet hosted by https://ffmuc.net/ a voluntary association in Munich with open source software. Donations may be necessary if this becomes too famous https://ffmuc.net/wiki/doku.php?id=ev%3Astart It is a non-profit. Based on https://jitsimeet.eu/ IIRC

There are some Jitsi Servers like https://jitsi.pirati.cz/ or https://jitsi.piratpartiet.se/

Emil Ivov, a student at the University of Strasbourg, France, creates SIP Communicator 2003. 2011 SIP Communicator is renamed Jitsi (from the Bulgarian “жици”, or “wires”).

IONOS Video Chat Very easy to use, no costs and no registration, with high data protection - only available for small groups of up to 24 participants IONOS is a german service provider Headquater IIRC Montabaur

Another alternative is Bigbluebutton for example here https://bbb.piratensommer.de/b Neustadtpiraten, the Hochschulpiraten Dresden, the Piraten Sachsen and the Piraten Dresden. They use the open source software BigBlueButton and Greenlight on a server from Hetzner (Germen provider) BigBlueButton was born out of the Technology Innovation Management (TIM) program at Carleton University’s Institute for Technology Entrepreneurship and Commercialization in Ottawa, Canada, and was launched externally in 2007.

Edit: In the meantime, there are probably Zoom alternatives listed. Digital Samba from Spain is probably free. And a few more with different cost models. Jitsi is not listed. Big Blue Button isn’t strict european (canadian)