To be honest you have to be more clear on this. In the screenshot the "Create broadcast" button is reachable indeed but grayed-out, so i assumed thats your problem.
Okay, you cant scroll while obviously the dialog is too big for your screen then?
Your display resolution in the Y-axis seems only 664px which is quite low. Sorry to hear.
Two hints i have. Please proof in the windows display settings that there should no text and content zoom higher than "100%" to be set. I know from my earlier days with win10 that windows default set "125%" there for my laptop display. I set back to "100%", so smaller text, icons and elements, but clear to view.
The other hint is: You produce in 1080p. Try if your display driver supports a virtual (enhanced in size) resolution instead. The virtual desktop would be wider and taller (than the physical display size) then, and windows scrolls the complete display content for you if your mouse reaches the top or bottom end of the display. (This function is not supported by all windows/graphics driver combinations.)
