When you are an ON resident but have a RL1, on the bottom of the T4 it will ask you to enter Box E form the RL1. That is all that you need to enter. 

The check box that say I worked in Quebec and received a Relevé 1 is not available in 2020.

• On the Income Slips step, check T4 - Employment income, if it's not already checked.
• Check I worked in Quebec and received a Relevé 1.