By default, if you want to move window or any popup, you have to click and hold one finger + drag by other fingers. It’s so hard if you move a long distance.
There’s one hidden feature allow you to do it easily. I’ll show you how, read below.
Open -> System Preferences
Click on Accessibility icon
Scroll down and select Pointer Control and Trackpad Options…
Here is it, change from “without drag lock” to “three finger drag”.
Save and try it. Hope it help ^^