Assalamualaikum ustadh, if someone says that he does dua after every salah and its just a routine for him, is it still bidah? because I heard that if someone reads quran for example after maghrib as a routine everyday it is fine.

Ustadh AbdulAziz al-Haqqan

Let him make dua during the salah, and the Prophet after the salah didn't do dua, he made thikr and we follow in his example