Anyone know why I cannot use this feature? (Not entirely sure if it's just this project or others too.)
The button is enabled when the selected form version has a tick under 'Built' column.
What adds the tick?
I needed to refresh to see the tick appear. Does this mean that you have to build it from within the version the first time?
Yes, the TM form version needs to be built from within the Maestro editor before the button is enabled. Once the TM form version is built it can be easily downloaded from the dashboard. Please note that any changes to the form will require the TM form version to be re-built within the Maestro editor.