Where does foreign alimony received get entered on my Canadian return? There seem to be two places, but I'm not sure which is correct.

You can enter foreign alimony on the foreign slip. To get to the foreign slip in TurboTax Online, use the “Find” tool (magnifying glass) to search for “foreign”. Select “Foreign Income” from the list and then click the “Go” button. 

If your foreign alimony is eligible for the Foreign Tax Credits, then you will enter the information again on the Foreign Tax Credits page. To get to the Foreign Tax Credits page in TurboTax Online, use the “Find” tool (magnifying glass) to search for “foreign”. Select “Foreign Tax Credit” from the list and then click the “Go” button.

This Canada Revenue Agency (CRA) page has more information on support payments from a non-resident.

https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/support-payments/payments-a-non-resident.html