I had figured that out already. I compared it with the first post and saw it was incorrect.@Bokkoman
were you having this same issue? if so, that explains why you couldn't get anything to work. the tar command needed a dash in the instructions provided by the post. If you want to retry, you might be able to get it to work.
Do you maybe have an idea to use the AdGuard auto installer? I think that would be the easiest solution. Except it is saying that curl isn't found out something.