When we insert an image from Content Hub, the Alt text comes from somewhere, it can be the Title Field or another field.
In this scenario, I could not select another field, below there is an article explaining how to change the Alt Text to an alternative field, However , This new field, it was not showing on the list
So what happened
Why my field was not AVAILABLE ON THE LIST?
The issue is the Field Support ONLY Single Fields, if the field is currently Multiline, It won’t show up on the list for changing the alternative text
So what to do ?
Change from Multiline to Single Line
and now after performing the change, we can see the field available on the list
Sitecore Tips 
You must be logged in to post a comment.