Thank you for your reply.
After several reinstallations, everything looks normal: I now have access to the templates. There must have been a bug or problem because half of the items available now were missing (only two or three items per menu!) and there was no template editing space.
I understand the choice to keep the data, but I don’t like extensions to leave traces – some plugins leave the choice, in the event of deletion from the admin, to keep the data or overwrite everything, I find that it is the best solution.
I make my own useful backups for security and the host does full backups daily…
Maybe this plugin could only keep emails and subscriber lists if deleted.
Yours sincerely,
François