How to create an OAuth 2.0 Client?
If you're building a custom integration to SendFox which requires users to authenticate in order to get access tokens to make API requests on their behalf, you'll need to create an OAuth 2.0 client. This is easy to do from the "OAuth Apps" settings page found here https://sendfox.com/account/oauth
Using the authorization_code grant type to authenticate users using OAuth 2.0 to retrieve an access token is fairly conventional, more information on that process can be found here: https://www.oauth.com/oauth2-servers/server-side-apps/authorization-code/
Access Token URL