I did some updates in the past against cryptic APIs for urls into the french pack.
A quick look at geneanet new API, maybe you can move, at least one old reference on the template (fr.csv), and replace it with a new one (deprecaded version ?). At a glance, to replace:
https://search.geneanet.org/result.php?lang=fr&name=%(surname)s"
by:
https://www.geneanet.org/fonds/individus/?go=0&nom=%(surname)s&prenom=%(given)s
Maybe also in english.
I do not know if this could be useful but:
$ curl https://www.geneanet.org/fonds/individus/?go=0&nom=nom&prenom=prénom
...
$ curl https://www.geneanet.org/fonds/individus/?go=0&surname=nom&given=prénom
...
$ curl https://www.geneanet.org/fonds/individus/?go=0&aeiouy=nom&blabla=prénom
...
this sounds like not to be the real “API”…