I noticed traps has 3 parts upper, middle and lower, if I do the shruging for upper part, and all rowing exercises for back could hit the middle part, but for the lower part of traps, I’m not sure which back exercises can hit this, should I include another exercises for lower traps, and what kind of exercise? and I’m wondering I seen other program just only shrug, but I understand that rowing exercises could also hit middle part of the traps, but what about the lower?

Traps actually have 4 parts. Traps 1,2,3,and 4.

Try this

DB Shrug- Primarily 1 Smith machine Behind the Back Shrug- 1 and 2 Reverse Incline Bench Db Shrug- traps 2,and 3 Reverse Grip Bent over Barbell Row- 3 and 4 Also do Prone Cobras