Isn’t that a second question?
Anyway, the way to poke things at the UI is to:
- open up the UMG asset
- click on the Graph button in the top-right corner of the UMG editor
- add a function called “set countdown”
- give that function an input that is the value
- in that function, forward the input value to the set text function of the text item in question
- in your game Event Tick (that calculates the timeout) you can then call the Set Countdown function on the UMG widget