Online simulator advice

Hi all. I am looking for advice/suggestions for online arduino simulators. I am teaching a 9th grade robotics course online. Typically the course is taught in person and we use the ardunio uno for our robots. Right now I am using TinkerCad's circuit simulator and I have also tried the Arduino online ide. Here are my constraints

  • I want the cost to be $0 (so students can continue using on their own after the course is completed)
  • I need something that is available in China without the use of a VPN
  • I hope to find something that does not have a large bandwidth

For now I want to keep any resources tied to arduino, due to subsequent course work in other classes.

thanks in advance for your help!