How to animate Light's Power/Strength in 2.80?

I know this was asked before, 4 years ago. But it's not working in 2.80.

You can do it the same way you animate most other quantities in blender. Go to a frame, set it to the brightness you want, then right click on the Energy slider and click Insert Keyframe from the menu. Go to another frame, change the value, and insert a keyframe again. Then it will automatically animate the brightness between those two points.