In SAP system, how can I find details of Change Request with modification?

You can view Transport request that contains detail about your changes by going to T-Code SE37. You have to enter the name of Function Module and click on Utilities → Versions → Version Management

Also note that when you don’t put the changes in $TMP package, the system will ask you to provide a Transport Request to save or activate your changes.

You can also check the package by navigating to Goto → Object Directory Entry in Transaction code: SE37 as below: