permalink plugin or change the name for the permalink

You can try adding a bp-custom.php file at the root of your plugins directory and add in it :

<?php

define( 'RENDEZ_VOUS_SLUG', 'agenda' );

With file zilla oder in wp admin ?

well if bp-custom.php doesn’t exist you’ll need to transmit it with filezilla. Please read the article about it in BuddyPress codex :
https://codex.buddypress.org/themes/bp-custom-php/

ok,

nserted into wp content
plugin

bp-custom.php

<?php
//define( ‘RENDEZ_VOUS_SLUG’, ‘agenda pubblica’ );
?>

Rendez vous in the user profile but do not change

you’ll need to go into your language file, and change this. You need to look into language editing in wordpress and buddypress.

the code you shared @ildexperience has no chance to work as you commented the line.

Anyway I’ll look at this in next upgrade, i will close this topic but you will be able to follow my progress here : https://github.com/imath/rendez-vous/issues/22