Transferring affiliate earnings to balance is not enabled
Affiliate payout with balance_transfer returned 403 because allowBalanceTransfer is off.
Why this happens
Admin disabled transferring affiliate earnings to account balance. External payout methods may still work. Distinct from amount/eligibility errors.
Diagnose and fix
1. Admin → Affiliation settings — enable transfer to balance if desired; save.
2. Member: use a normal payout method, or retry transfer after enable.
3. See Transfer affiliate balance to account.
4. See Request a payout for cash-out methods.