PayPal checkout is not configured — add REST credentials in Admin → Settings → Payment Settings and enable PayPal checkout
Role-plan / session checkout refused PayPal until REST credentials are saved and checkout is enabled (full admin path wording).
Why this happens
Credentials or enable flag incomplete before creating a PayPal order. Sibling of the shorter Payment Settings message and the “not enabled” assert.
Diagnose and fix
1. Admin → Settings → Payment Settings — paste client id/secret; turn on PayPal checkout; save.
2. Confirm sandbox/live matches the PayPal app.
3. Retry premium checkout with PayPal.
4. If enabled but order create fails, see order-creation / confirm articles.