yannick-9560, Following-up from my private comment:
From the sample, you may be using routes.json-
note that, the functionality defined in the routes.json file is now deprecated and better implemented in the Azure Static Web Apps configuration file.
Kindly see these docs for sample configuration and see if that helps.
https://learn.microsoft.com/azure/static-web-apps/configuration#routes
https://github.com/Azure/static-web-apps/wiki/routes.json-reference-(deprecated)
If the issue still persists,
Could you please share your Azure static WebApp name (reply to my private comment) and additional info about your requirement/scenario (here)?