Need to find a "professional grade" COPPA-compliant coding site for under-13s!

One of our teachers has been using https://repl.it to teach Javascript and Python programming to our 8th grade students. Even though it has a site designed for “teachers”, the company has no intention of complying with COPPA (they say the “paperwork” is too onerous). Unfortunately most of our 8th graders (and we could be using this curriculum for 5th graders) are under 13 years of age.

Can anyone recommend a similar, “professional grade” coding site that does allow under-13 accounts (with school and/or parent consent, of course)? I don’t think it’s right to have parents own the accounts and let their children use them, but I guess that might be technically legal.

What’s nice about Rep.it is that it covers multiple languages, and supports teachers with a “classroom” feature that pushes out assignments to students. The downside of Repl.it (and most of the other similar products I have found) is that they use social media to allow users to share their code. Twitter and Facebook are of course off-limits to under-13-year olds.