Can I buy an Apple SIM card if I’m not a resident of the country where it's sold?
Yes, you can1.

I can confirm that you are able to get an Apple SIM, regardless of the status of residence in the country you are buying it in. Buying an Apple SIM does not require registration.

In Canada, it cost CA$5.00 for one.

1Can’t find a source, but I tried it out.