Basic Authentication and Exchange Online – February 2021 Update

I was wondering if you could please tell me if a certain form of authentication is classed as basic and potentially should be replaced. I am currently developing an Outlook add-in that needs to save the emails and attachments of clients to our database. I've used the Microsoft document "Get attachments of an Outlook item from the server" that uses Office.context.mailbox.getCallbackTokenAsync and Office.context.mailbox.ewsUrl to get a valid token to pass to our API. The API then coding ExchangeService service = new ExchangeService, Credentials = new OAuthCredentials(request.AttachmentToken), Url = new Uri(request.EwsUrl). Is the above methodology classed as basic and needs updating?