One friend of mine is constantly arguing with me that asking for help from Mola Ali (as) is shirk. He keeps quoting Quran that in it Allah has constantly said that ask me and I’ll help you than why do Shias ask Ali as for help. How can I answer him from Quran as only needs answer from Quran.

My advice to you is to prove to him asking Prophet Muhammad is okay. Once you do that then move on to Imam Ali. Use this verse Nisa 64

وَمَا أَرْسَلْنَا مِن رَّسُولٍ إِلَّا لِيُطَاعَ بِإِذْنِ اللَّهِ ۚ وَلَوْ أَنَّهُمْ إِذ ظَّلَمُوا أَنفُسَهُمْ جَاءُوكَ فَاسْتَغْفَرُوا اللَّهَ وَاسْتَغْفَرَ لَهُمُ الرَّسُولُ لَوَجَدُوا اللَّهَ تَوَّابًا رَّحِيمًا (64)

Also, the fact that Allah tells us to pray in the Maqam of Ibrahim