Unfortunately, there is no process in place right now to settle Verbal Authorizations given by Merchant Bank or Customer's Issuing Bank in NetSuite. You can only process or settle these authorizations outside of NetSuite.
Kindly contact your Payment Gateways (i.e. CyberSource, etc.) directly to know how you can process these transactions on their end.
For customers asking to have the ability to process these transactions inside NetSuite, they can have their case attached to the Enhancement Request below:
Enhancement 227898 – Ability to process Verbal authorizations in NetSuite