Welcome to the Auth0 Community!
The user in the question asked for an embedded login experience and passwordless connection. The linked docs are mentioned specifically for regular web applications. For single-page apps, this setting is disabled.
Depending on your needs, if you want to use the new Universal Login or Embedded login, there are different approaches you need to take.
In terms of the new Universal Login is the easiest way as you only need to create a passwordless connection with email and enable Identifier First in the Authentication Profile
If you want the embedded Passwordless Authentication for either SPA or Regular Web applications, check our docs about these two methods.
I hope it will help
Thanks, and have a great day!
Dawid