Hello Riccardo Barbieri,
Thanks for your question.
Ensure that the certificate is indeed created and associated. Use Azure CLI:
az containerapp env certificate list --name $name--resource-group $RG
If the certificate exists try binding: https://learn.microsoft.com/en-us/cli/azure/containerapp/hostname?view=azure-cli-latest#az-containerapp-hostname-bind
az containerapp hostname bind -g $RESOURCE_GROUP -n $CONTAINER_APP_NAME --hostname --environment $CONTAINER_APP_ENV_NAME --certificate $CERTIFICATE_ID
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Abiola