Normal 1st class standard can take 2 days to weeks. As it's not priority. it's comes down to just being patient when chosing that option. The old dark web way. If it's a well reviewed vendor should be fine. if not just msg them and try get an update. From experience it's being patient with the delivery option you chose.

Same thing happened to me. Have ordered off of countless other vendors with no issues, but this particular one was sent last Wednesday and hasn't turned up in 8 days. There are other people on their reviews saying the same thing has happened with regard to packages not arriving.