Is it possible to add ALT TEXT to a GIF created with Adobe Express?

I'm dead chuffed to have created my first ever GIF with Adobe Express!
However I cannot find a way to attach ALT TEXT (to help people with visual disabilities understand the content).
With alt text when someone using a screen reader comes across a picture/GIF they will hear the alt text describing the picture; without alt text, they will only know they've reached a picture without knowing what the picture shows.

I'm sure this must be possible given Adobe is super aware of these things, can anyone point me in the right direction please?
I'm on a Mac running latest IoS.