Ok thank you.

I learned about the limitation elsewhere. What a shame, but it makes sense that Apple would not want to encourage anyone to test or support older Operating Systems. Thanks for taking the time to reply!

Someone on Mastadon pointed me to this helpful page https://eclecticlight.co/virtualisation-on-apple-silicon/ and I successfully got a VM running! However I can't sign in to the App Store. No matter what I try it tells me in red "The action could not be completed."