Why not use one of the many templates the man behind the program have made allready.
In essence the most simple thing would be to do something like this on upperbody days:
Bench or OHP: 5/3/1.
An additional pressing excercise( dips variations, bench variations, OHP variations etc ):3-5 sett x 10-15 reps.
A row variation: 3-5 sett x 10-15 reps.
A chins/pulldown variation: 3-5 sett x 10-15 reps.
This is simple and it is balanced since you do as many pulling excercises as you do pushing excercises.
You can also add stuff like curls, tricep isolation, rear delt fly etc if you want and have energy for it.
You can also do bench as the secondary lift on the OHP day to increase both benching frequency and weekly benching volume.
Hope that was any helpfull.