Wait time in dynatrace is active wait time where your code waits on something, e.g. with Object.wait().
You can analyze it more in the Method Hotspots. There you can see which Methods cause the wait and see from where they are called in the reverse StackTrace.
When I try to check the method which causes the wait time then I get only inbuilt frameworks and not getting any method related to the application, then what will be my next step to reduce that wait time. can you please guide me.