a valid visitor visa or eTA
a valid passport
to tell the airline that you’re exempt from the travel restrictions
to show an immigration officer that you’re coming for a non-discretionary purpose, such as to live with your spouse, common-law partner or family member
You’ll be refused an authorization if an officer finds that you’re travelling for an optional or discretionary purpose, such as for tourism, entertainment or recreation.
to have your health checked by airline officials to confirm that you don’t have symptoms of COVID-19, including a fever, a cough and difficulty breathing
Anyone showing symptoms will not be allowed to board a flight to Canada.

Maybe we will travel directly from U.S.
I know I will be qualified via a specific employment work permit but I'm not sure if my spouse's visit will be treated as a non-discretionary purpose.
That's why I'm asking for the answer. thanks

1)they’re travelling directly from the U.S. for a non-discretionary purpose
2)they have a written authorization from IRCC to reunite with a temporary resident of Canada (see Uniting with immediate family members for more information)
3)they have a letter of introduction for an open work permit