Glad to hear you have a solution…but I think that might only work for PRO users? (Not sure if your students have PRO licences or not?)
In terms of sharing a project, the new way we recommend is to use the project page URL. These are unique to each project too, but they have the added benefit of not expiring. For example:
https://x.thunkable.com/projectPage/5b2b8c430350869f967c6acf
Hope that helps.