Can't update custom parameters of an automation app

I’m trying to update custom parameters from my lambda function with a PUT to https://api.smartthings.com/v1/apps/{myAppId}/settings but i get this error message:

“name”: “StatusCodeError”,
“statusCode”: 403,
“message”: “403 - undefined”

Is this related to a permission missing ? How can i add that ? I tried with the Oauth API but “w:apps:*” permission was unknown.