[Rey_a]

It is not MobileSheets that is suggesting to install the update, it is the app store on the device your running mobilesheets on.

To disable install :
In the Microsoft Store, click on your profile icon (top of the window), choose settings and turn off the 'app updates' slider.
In android, open the Store, click on the black circle with a white letter in in the top right corner of the screen, Choose 'manage device and apps' (first option), click manage at the top of the screen, look for the MobileSheets app and select it, then choose the overflow menu (3 dots in top right corner) and turn auto update off.
It should be possible to do this on iPad Os as well, but I never have done it, so I do not know how.

My devices are not in english,, so the english phrases above may be a bit off, from what you actually see on the screen.

Rudy