There are several options for processing payments using Chargent. You can Authorize the full amount, Authorize the minimum amount, or Charge the full amount. Authorizations verify the funds are available or the card is valid. Charge will capture the amount and process the transaction against their credit card.
With FormAssembly they do have a way to Authorize the credit card.
Keep in mind that Authorize through Chargent is only available for one-time purchase and can not be used for ACH or Recurring Billing.