There is indeed. The person who you want to credit will need to have a Racesignup account. On the top menu tap on Credit Balances. Search for them. Tap on their row and the credit transactions appear in the lower table. Choose one of the rows in the lower table and tap on the “Duplicate this record” button. Change the details in the Credit Line record. Select (none) as the event so that this credit does not impact on the event’s credit records. Change the amount and the note. Tap Save New Record.
If they haven’t had a credit in the past then they won’t appear in the upper table. You can still give them a credit. You’ll need to know the email address they use for Racesignup. Select anyone in the upper table and then do the same as above but also change the Account email to their email.
Please note that this method is primarily to reward volunteers or officials who haven’t entered the event. For helpers who are competing, the best method to reward them is to have a Discount.