Communauté

je n'arrive pas créer le sandbox, c'est pour les services de pelerinages qui font deja la paiement classique, on besoin tester l'api direct. merci

sandbox shows our test association service-pelerinage-test as not verified. So that’s very probably the step that’s missing. Two points from the reference page for creating a checkout:

Unverified association: HelloAsso documents a 409 error for this case, while we get a 404 … "form". So it’s likely the cause, but not proven.
Checkout permission: the API client needs the « Checkout » permission. Without it the answer would be a 403, not the error we get.