On a " goodbye" tax return, how do you declare Canadian source income earned outside of Canada as a non-resident if that income is included in the T4?

We left Canada on June 29, 2023, but continued to work for a Canadian employer until August 31, 2023. This income that we received as non-residents for 2 months is entered on the T4. If we indicate that we were factual residents in Canada for part of the year and then moved away, the system will ask us to indicate the income from Canadian sources for the part of the year that we were not in Canada. What should we enter there? We cannot separate the outside-Canada payment in the T4 from the payment we received while we were residents in Canada.