I would say 2 Prairial an 7
Here's a link to the Acte de naissance but the language looks more German / Alsacien to me. https://archives.bas-rhin.fr/detail-document/ETAT-CIVIL-C485-P1-R254545#visio/page:ETAT-CIVIL-C485-P1-R254545-1812503
It's German. In this 'acte' the day of birth is 1 prairial an VII, so 20th May 1799.