Hello, I am making an application for people who work in cleaning.
My issue is the following : The goal is as follows : the operator clicks on the “Start the mission” button, this redirects to the “missions in progress” page. I would like to hide this page which is called “missions in progress” as long as the operator has not clicked on “Start the mission”, I have been looking for a long time and I am really counting on you to help me 
Have you tried adding a custom action that includes a Set Column action upon button click, which sets a boolean column to True and then setting the page visibility to only show if the boolean is true?
Should probably make the boolean User Specific unless you’re using the User profile sheet
You could also make the page hidden by checking the box “hide in navigation”. Then, the ONLY way to get to this page would be via a “go to page” action or the deeplink.
Following on from Joe, that’s kinda how I’ve done it - but I’ve used the User Profile table. I added and extra column, in your case it could be ‘Mission Ready?’, and then I set it to ‘1’ if they click the button using the ‘set column value’ action. You can then set it to go back to zero if you need to at some other point, or after a period of time using some if/then/else logic. Obviously you then need to set your visibility of the page to 'only when Mission Ready? = 1. It’ll always be user specific too!
As an aside, and following on from Robert - you can make it so that the page is hidden, but going further - you can make it so that the button that you said they clicked that redirects them isn’t visible unless they’ve clicked the ‘Start the Mission’ button. Use the same logic as on the page, only apply t to the button - if Mission Ready =0, don’t show the button.