Tax for Non resident

My customer was non-resident of Canada. He worked in Canada for US company and did not live here for more than 183 days. He has W2 as well as T4.
Can someone help me for:

  1. Should I file his Canadian tax return?
  2. What deduction is available for him?

From the information given, he was living in the US. If he has renounced his visa often called Green Card in 2020, he will do a 1040NR and a state return where he earned the income first then a Canadian. If he has not renounced then it becomes more complicated. You would calculate the US and state first, then do the Canadian showing world wide income and claim the foreign tax paid in the states. Not having renounced his visa, he is considered to be a US person and would do a 1040 showing worldwide income and claim foreign tax credit for the Canadian part of his income or the foreign income exclusion on Canadian income

Thanks for reply, but what is foreign income exclusion?

Oh I checked foreign income deduction, unfortunately it doesn’t apply in my case.