Welcome to the Auth0 Community!
I understand that you are getting Errors when integrating Auth0 into your existing app.
After taking a closer look at your attached error, it shows that your app failed to compile because of the
Module not found: Error: Can't resolve 'crypto' error.
I found that this is a known issue and several users have reported workarounds on Github:
Please open a new issue in the repository if your problem persists even after trying all the suggested workarounds.
Please let me know if there is anything else I can do to help.