how to setup sales agreement for order management

Summary:

as mentioned in the implementation guide i have created a new contract types as the only set up task for the sales agreement and chosen the Reference Data Set Name but when i try and create a contract the business unit name is not visible and i have checked the assign business unit business check and the contracts box is check , another problem

i have setup the service contracts or another legal entity connected with another Reference Data Set and only that Reference Data Set data such as the BU , legal entity and the contract type are the only options that when i try to create a contract.