Trello flow to buffer

Hello together, i planned to build a flow from trello to buffer.
If i move a card in trello to a named list the trigger starts. The next module is also
trello to get the card ID. The third now is buffer.

I got the text and the time into buffer, now problem. everythings start in the planned time. But if i will do it with a pictures as an attchement i got mistakes. I really don’t know how i can upload or how is the entry for media in the buffer window.

I tried a lot of possibilies.

Maybe someone can help

Thanks a lot