so I assume it is supposed to be displayed in the Browser (via AccessPoint)?
In that case, unfortunately you cannot quite do it - in the main menu "Display", there are a few options to "fix window size" and "zoom" - maybe you can find a fitting setting there - but generally speaking, what you have in the Client - where you develop your apps - is not exactly what people will see via the AccessPoint. You have to test that,. and the users will have to use the zoom of their Browser. Sorry.