You have to add the "get player character " node - drag the link from “Return value” out - type in “mycharacter” (or the name of the bp that includes the timer part) - coose cast to…
For the trigger I have just created a new actor blueprint.
Then I added a box volume in the component tab
Now in the component tab in the properties you can create an event out of it -> oncomponent begin overlap
After that it should jump into the event graph
Now add the nodes on the picture 