How can I
The top left button in the debug window (the green triangle) is doing what you want. "Resume Program (F9)"
you should do the followings to enable the debugger option - https://developer.android.com/studio/debug
Breakpoints are toggled by clicking in the narrow column to the left of the code. You can also have conditional breakpoints, for example by right clicking the red spot I could enter someVariable > someOtherVariable
. Other options include suspending the whole app, or just the thread that encountered the breakpoint.
Buttons going down the left
Buttons across the top