You can use the Group Policy tool for Windows Pro and it can be enabled on Home. Here’s a pic from me having done it on a PC (that is not actually capable of running it anyway, so this was just a test to see if I could get rid of the “nag message” (which it did not.)) Note that this will forever lock you to one specific version, as specified, and you will need to eventually update it to something like 21H2 when that releases.
[Hmmm, having problems uploading the picture… must be too big. I will try to resize it some, and hope the usefulness is not eliminated.]
Well it seems like Discourse is having a bad day, so try here: https://snipboard.io/sTkqZb.jpg
Press START then start typing gpedit.msc and run it with elevation. After, you may also want to start an elevated CMD prompt and run gpupdate, to make sure it applies right away.