This letter allows for exemption from quarantine. The OP still needs a visa as stated,
“This letter is not a travel document and does not, on its own, authorize you to travel to Canada without a valid passport, visa or electronic travel authorization (eTA) that you may require to travel to Canada. To board your flight and/or to enter Canada, you must continue to meet all the usual eligibility and admissibility requirements in the Immigration and Refugee Protection Act (IRPA).”
The PHAC forms are on the website but you still need a TRV or eTA
https://www.canada.ca/en/public-hea...te-entry-limited-release-from-quarantine.html