As per the site, Your immediate family members may be able to come with you to Canada. They can travel to Canada if they meet one of the conditions below:
they’re travelling directly from the U.S. for a non-discretionary purpose
they have a written authorization from IRCC to reunite with a temporary resident of Canada (see Uniting with immediate family members for more information)
they have a letter of introduction for an open work permit
As per the site, Your immediate family members may be able to come with you to Canada. They can travel to Canada if they meet one of the conditions below:
they’re travelling directly from the U.S. for a non-discretionary purpose
they have a written authorization from IRCC to reunite with a temporary resident of Canada (see Uniting with immediate family members for more information)
they have a letter of introduction for an open work permit
It is not written anywhere that you don’t need an exemption letter. You need an exemption letter as i stated above and with the link. Click on “how to bring family members with you.” You are on a visitor visa not a work permit. Your husband has a closed work permit and therefore a job offer so he doesn’t need authorization.
Not in all cases but you are a visitor and your spouse is a temporary worker. You don’t have the same rights as immediate family members or citizens or PRs. I am stating what is on the site. Maybe others who have done it without authorization. However you don’t want to pay airfare and be denied boarding because you don’t have authorization when it states you need a letter. You also need negative Covid tests too now. All the best.