How to display real time information in Details panel during editing by Blueprint?

For example,
I have a Spline Blueprint Class.
I would like to have an extra variable called “PointsNum” in the Details panel. Show me how many points in the spline during editing.
When I add a new point, “PointsNum” will +1 automatically.

Can I achieve this feature by using Blueprint?

Update your variable in the Construction Script.