Get Call for Supply Request taking time to give Transfer Order Number post its creation

Supply Request API (/fscmRestApi/resources/latest/supplyRequests) is taking time to give results of Transfer Order details. Use case here is that through REST API post method call we create TO and then to receive transfer order details we use the same rest api get method call. The get call takes time to give the results back and in OIC we have to add wait till the transfer order number is generated. Client does not want to add wait in the code. We want to know the best approach to handle this case. The goal is to fetch the Transfer Order number as