Thanks Daniel !
I do understand now that the plugin requires to work with Gutenberg.
As I use an wysiwyg (non opensource unfortunatly) plugin to design the website (for ease of use as I’m a noob), i did not activate Gutenberg it until now.
Now I can see Connector and I managed to plug it to a page : ma-bo.fr/agenda-benevoles . I’ll test the connection to our account very soon.
Thank you very much for the reply and for your work.
Kind regards,
Fabien