I am currently working on a project where we are trying to implement our own login and sign up system which uses the PKCE flow. The tools we are using are react typescript and node js with an express server, all running on localhost. The flow works, but the problem is that to login and get the authorisation code through the /authorize endpoint you have to go through the auth0 login page. I know that you can change the HTML in the dashboard for the login but this would not be ideal for our current situation. We would like to implement our own UI with react, which was possible for us using the auth0.js SDK but since this uses the implicit flow its not what we want to use. So my questions are:
Is there a way to implement the PKCE flow and use our own custom login pages created in React?
Is there an endpoint I can reach in the authentication API from my application where I can send the login credentials and code challenge, to then get back the authorisation code?
What other alternatives to this exist in the case that you cant implement your own custom UI for login if I want to achieve something similar to the PKCE flow? Or is my only option to change the login page by using custom HTML in the dashboard?