Get German VOIP Number to Receive SMS in USA

My dad does a lot of buying old car parts on German eBay, but there is apparently a new requirement that you need a German phone number (for SMS verification codes, I guess). I was hoping to help him out with this.

I'm based in the US - what is a good way to get ahold of a German phone number for SMS codes? I was thinking maybe Twilio (I'm a software engineer and I've used them before) but it's kind of pricey at $6/month and requires a local address. My dad has a German P.O. box but I'm not sure if that counts. I was going to wire it up to just forward SMS messages to his email.

Is there another way? I know this use case is pretty specific, but I thought if anyone knew about getting VOIP numbers it would be privacy folks!