On FF it seems sort of fiddly. It should capture (or ask you if it can) any time you click in the window, but in practice sometimes I have to click twice, some

On FF it seems sort of fiddly. It should capture (or ask you if it can) any time you click in the window, but in practice sometimes I have to click twice, sometimes I have to right-click and then cancel the RMB menu, etc. YMMV...