COVID tests in the US to be able to fly back to Canada? Any recent experience??

Random COVID-related question that probably shouldn't spark any arguments....

I have a British Columbian friend who's been in the States for a while (family stuff).  They're looking to get their vehicle (which is in the BC interior) down to Washington state and can't easily make the trek up north to grab their car, and then drive it back down south.  I'd be potentially interested in driving it down myself, if I knew I could relatively easily get back into Canada right away.

I've been hearing that COVID tests (PCR and NAAT included) can sometimes be had for free, and some with relatively quick result times too!  This apparently (sometimes) applies to anyone - not just US citizens; but it is very much dependent on where you were in the US.  Big pharmacies like Walgreens or CVS, or even little guy mom n' pop pharmacies are reporting to have done these tests for travellers.

Quick google searching makes me think it would be difficult to get a quick, free COVID test in Spokane, but in Seattle, it might be easier.  I've got a regular old day-job, so I'd only have 3 or 4 days off to work with, and really couldn't just end up stuck down in the States because of a logistical COVID testing issue.  Or, even worse, if I somehow caught the 'vids whilst being down there, and then had to deal with the delay/potential illness involved in trying to make my way back up north via an aeroplane.

Anyone have any recent experience with this sort of COVID-testing conundrum?  Specifically, for trying to get tests done in Spokane or Seattle?