I don't know my deceased partner's income as I am not his executor and I do not allow to do his tax. Can I skip this part? Can I choose "O"$

I'm sorry to hear of your loss.

If your partner passed away in 2022, the Canada Revenue Agency (CRA) will still require their information on your return, and your information will be required on their return.

You can enter an estimate for now, and then put in the actual number before you file.