Wiper fluid, dumb question

[Dannyo]

I have a 2017 Alltrack S..... Wiper fluid low displayed.....Since the owners manual is kind of obscure, how much fluid? I can see the blue cap and the fairly long tube but see no fill to markers. How much fluid does it take and how do you know if it's filled?
TIA
Dan

 

[ATXGolf]

I just fill it till its close to the lid.