The captureOnly action code is to be used as a separate transaction after authorization only payment transaction is processed and successful.

Note: To test this feature run a test "captureToo" request. Remove the "Yes" in the captureToo field, this will result in a approved authorization only request. Use the Transaction ID from response when submitting the Capture Only request

For testing, set the following fields after selecting the "Try It" button
externalReferenceID = Unique record identifier for processing - you assign Numeric Min = 16 Max 19
transactionDate = Set to UTC timezone, Format 2020-09-15T17:01:01
Link to UTC time =

Click Try It! to start a request and see the response here!