You can claim the Canada Caregiver Credit if your father depends on you for support because of a physical or mental impairment.

The CRA may ask for a signed statement from a medical practitioner showing when the impairment began and what the duration of the impairment is expected to be.

https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-re...