You will have to do it in the blueprint’s graph.
You will need to get the status component of the player
And if you are wanting to add to a value instead of just set the value, you will need to get it via this method
and just storing or using the return value.
To then set the number in yellow you are talking about you will need to use this func,
Keep in mind that modifiying max stats is not something that ‘goes away’ after the buff goes away. If you want to return them back to normal when the buff ends, you will need to set the max stat back to original value.