@Hexasoft explained on the French Wikipedia bot request page to have lost the access to the Hexabot account. Hexasoft is checkuser and sysop on the French Wikipedia.

There is a long standing link between the two accounts (bot account and contributor account). As such, the request is trivial enough to proceed immediately. A French Wikipedia trusted contributor, El Pitareio, confirms the triviality of the request.

Identity checks

• Assert there is a very well known link between bot account and contributor account (table récapitulative des anciens comptes bot)
• Check by mail with the contributor the request is legit