Service to run code in the cloud for a programming textbook?

I'm in the process of building a programming school. The primary form of education is a textbook I'm writing. I'd like to embed programming exercises in that textbook which the user should be able to solve directly on my website – that is, write code, run it and see if it worked. I'm looking for the best services to build a prototype with minimal effort. I am currently considering a no-code stack that involves e.g. Webflow and Airtable. However, I'm missing a service that can execute people's code. What I'm looking for is a service to which you can submit code from an HTML form, and this service gets back to you with the output of that code's execution. Ideally, it should be possible to integrate it in Webflow (or similar builders) via Zapier. Can you recommend any service like this?