Joining a branch drain line at a 30 degree angle?
How do plumbers get a 30 degree angle from PVC ? 

There are lots of ways to go about it for example reworking your plumbing, but the easier way is to just buy the 30 Degree PVC pipe that you need.

Below is not an endorsement but a reference for where you can get it .. of course a plumbing supply might have them in stock and on hand for same day pickup ..

https://www.supplyhouse.com/PVC-Schedule-40-30-deg-Elbows-15206000