The action code "makeRecurring" can only be used in conjunction with the “captureToo” flag set to “yes.” allowing you to create a recurring transaction during the initial sale request. which will create a recurring payment when the initial payment is approved.
N O T E:
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
Link to UTC time = https://time.is/UTC