I am using the ruby-trello gem, and I am having some difficulty adding an Attachment to a card.
Card created without problems. Checklists added, all good.
When I try to create an attachment with
Trello::Attachment::create(url: 'Some URL here')
I get an error: TypeError (no implicit conversion of nil into String).
Am I missing some required values in the creation or have I got the whole thing wrong?