Caftsman Club 3D Printer Sweepstakes - won't accept email address with dash

I tried ot enter the Caftsman Club 3D Printer Sweepstakes but the form will not accept my email address because it has a dash in the domain which is valid.  Please fix.

Kiteman4 years ago
What sweepstake?

Can you give us a link to the page you're using?
I think he means this one: https://www.instructables.com/craftsman/
It is only for people from the US, though
Dang, how did I miss that?

@rwollin, send an email to support@instructables.com and ask them to check into it.