Hi.
I used to create custom apps and then use the API secret in the header of a REST API endpoint, using X-Shopify-Access-Token: shpat _xxxxxxxxxxxxxxxxx, in order to make requests. And this worked fine up until a couple of days ago.
Now when I create an app I still see the API Key and Secret, but the format of the API secret seems to have changed.
It used to have the format ‘shpat _xxxxxxxxxxxxx’ but the shpat _ prefix is not included in the generated tokens anymore, and the API requests return an “Invalid API key or access token” error.
Did the way of authenticating with Shopify change?