PaygateDeveloper documentation
404merchants.bank_account_not_foundmerchants

This merchant has no default bank account

Returned by the implementation; no specification rule declares it yet.

Something needed the merchant's default payout account and there is not one — no account has been added, or the one that was is removed.

Why the API refuses

this merchant has no default bank account

What to do

Add a bank account; the first one added becomes the default. See merchants.invalid_bank_account for the format.