Enable mouse support in Emacs
Summary:
F10, “Options” → “Customize Emacs” → “Options matching Regexp…”. Type mouse
and Enter.
Go to “Xterm Mouse mode”.
Press Enter on “Show Value”. A “Toggle” button appears, press Enter on it. Then press Enter on the “State” box and choose “1” for “Save for Future Sessions”
More complete info here: How can mouse support be enabled in terminal Emacs? - Unix & Linux Stack Exchange