Exactly, it's a Salesforce feature, basically you have all the information about this way to authenticate against salesforce just on their official docs here:https://help.salesforce.com.... In our project we use `https://github.com/zetachan...` and because of that we can set the `SF_OAUTH_URL` in a external configuration file, but in our case the value is the default from Salesforce (https://login.salesforce.co....

The redirect URL is coming from Expo, you don't need to know it, basically allows the browser to back to the application when the auth process finished, something like https://auth.expo.io/@yourE....

I hope this answer helps you 🙌

This looks very interesting, but can you tell me more info about the webservice that you are using?
Because Im also using Salesforce as a backend for my Expo app. I already have a simple email/password login, and I have a webservice for that.

But for facebook and google authentication, do I need to create another web service for that? Is that a feature of salesforce? How did you handled it?

what is SF_OAUTH_URL? is that an url to the salesforce webservice or something else?
And what is the redirectUrl?