whats alternative bottom of Shift+MMB

I want to know please, cause my MMB is very hard to press in,

thank you

In the user prefs window, you can choose to emulate the MMB.

can you be more specific ? where is that window?

Do yourself a gift and buy a good mouse. They are cheap nowadays and it’s a pain to work in Blender with a 2 buttons mouse.

Pull down the User Prefs window from the bottom border of the top header bar. Goto ‘View and Controls’ and set ‘Emulate 3 Button Mouse’. Close window. Now you can use Ctrl-Leftclick as MMB emulation. If you like it that way Ctrl-X to start a clean .blend and Ctrl-U to keep the change you made in User Prefs.