Hi, I'm working in developing and application for my company to allow users to buy devices, we are using Angular + .NetCore. We have implemented the IFrame without any issue. The problem is when we are going to do the charge and other Rest Api Calls, because we need to have and OAuth Access token for that, but the applications is going to be used by external users. The current process to obtain an access token is to access the authorization Url and get the authorization_code, then we can get the access_token using that code (obviously the external users won't be doing that).
We need to have something similar when using the WordPress plugin where we only set-up the required tokens/keys only one time and the all the external users can make the payments without having to authenticate or something like that.
How can we get an OAuth token only one time and then store it securely on our backend to use it whenever an external user buys a device from our angular app?