You can only claim parking fees as a medical expense if you were required to travel to obtain medical treatment.
Here's a good resource from the CRA on eligible travel expenses for medical treatment: https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-re...
Here's how to enter eligible travel expenses for medical treatment in TurboTax: https://turbotax.community.intuit.ca/replies/2648074
