Ducati MULTISTRADA 1200S ABS 2015 Workshop Manual page 776

Refitting the fuel tank
Reposition tank (8) on the frame by fitting the two forks on support (9).
Fix the tank by means of screws (7). Check for the presence of the lower (14) and upper (13) blocks and spacer
(12).
Connect the two breather pipes (10) and (11) to the tank plug.