Hi,
It is not clear for me why in the case of using OAuth signin there a form opening and asking for the user and password since I already have an open session in the browser.
Hope I was clear and I will get an explanation:)
Best Regards,
Remus
Hi @remyvrs, welcome to the Postman community forum 
The Postman app runs in an isolated webview. If you are trying to do an OAuth authentication flow in the app to get the access and refresh tokens for your requests, it will open this isolated webview. This does not use any existing browser session that you may have.