I'm trying to get 3rd party cookies to work on major mid-year 2020 browsers [1]. It's as simple as pointing an iframe to an external URL to make a cookied request and probably get the response thereafter (and the external site explicitly allows this).
Is there a solution to this problem? For example, some other header/s which the external site would set other than multiple combinations of Allow-Access- headers which simply doesn't work?
[1]: including Chrome incognito and iPhone safari.
