We have an approved player card but we can’t use HTML5 player because allowfullscreen param is missing from the iframe on Twitter website.
Here is a sample tweet which includes our player: https://twitter.com/BieNorHU/status/648483567673212928
You can see there is our Flash player which we have to to fall back to because of the lack of HTML fullscreen. In our HTML5 player the browser fullscreen API would be utilized to go to fullscreen but it requires the allowfullscreen iframe param to work.
If you check the dom, there are two iframes on the page around the player, the outer one is the twitter player card (https://twitter.com/i/cards/tfw/v1/648483567673212928?cardname=player&earned=true&lang=hu#xdm_e=https%3A%2F%2Ftwitter.com&xdm_c=default5022&xdm_p=1) which has the allowfullscreen param. However, there is an other iframe below, inside the ‘ExternalIframeContainer’ div which load our player itself and it does not include allowfullscreen param.
Please add the allowfullscreen param to this iframe too.