Approves a submission in the completed or rejected state:

• If the form creates partner accounts, a new partner account is created from the answers and activated. When the submission is for an existing partner, that partner and its live listing are assigned to the new account.
• If the form also sends invitations, the applicant and each contact entered on the form (one per email address) are invited to join the account with the form's roles. Invitation emails are sent unless your marketplace turns them off for form approvals, or the form is a registration form that lets applicants set their own password.
• A form.approved event is sent to your webhooks, and the form's automations run.

Returns the approved submission. The response can show vendor as null even when a partner account was created; retrieve the submission again to see it.