How to find the source domain for Facebook Oauth authentication?

[mpaezmolina]

Hi! I need to authenticate with Facebook using its OAUTH flow. But for FB to allow me to do that, I should specify the domain from which the request to FB will be made. I added the domain of my app with the format "appname.myshopify.com", also "myshopify.com", but stills FB complains that the domain from which OAUTH is starting is not a valid one. I think maybe, as this is an embedded code inside the Shopify framework, that the request is done from another domain. I try to check the network communication with Chrome but not finding anything.

The code to start the FB oauth process is called inside a component using the function for that purpose of the FB SDK. (FB.init(...))

How can I get the source domain or ip address from which the requests of my app are originated?