How to revive (or take over) a plugin?

I have been using a neat plugin to make sites multilingual. The last update to the plugin was 5 years ago – and it is broken as of WP 5.5.

I have signed up to the WordPress plugins site, but can find no way to sign up to (or even contact!) a project. Nor can I find a contact for a site moderator or suchlike.

How do you do that? How can one take over leadership of an abandoned project?