I am a US Citizen that received a small lump sum payment from private pension plan in Canada. I have form NR4 from Canada. Where does the info get inputted in TurboTax?

All foreign income regardless of why you receive it, is dealt with under the Personal Income tab in the Foreign Earned Income & Exclusion section.

All foreign taxes paid to any foreign taxing authority for any reason is dealt with under the Deductions and Credits tab, in the Estimates and Other Taxes Paid section. THere's a sub-section in there for foreign taxes.