Kindly refer to the following link(s):
Praying to the dead for intercession
Ruling on seeking waseelah from Prophet
Praying to Allah trough the Prophet as wasilah
Making dua to Allah by saying: Please do this for the sake of your beloved Prophetﷺ
Can we make dua to Allah through Prophet salla Allahu alaihi wa sallam?
Popular Daee from US said asking intercession from dead is not shirk but means of shirk