In the appstore there is an idle timer widget, this allows you to call a microflow after a period of inactivity by the user. You can set the length of inactivity and then run a flow to provide a popup with those options. However if you are going to do this I would suggest adding a second timer to the popup. This is so after a set time it would then logout the user. The reason is because if you have sensitive information on your screen and you leave your PC, you don't want someone to be able to press continue and have access to your data. Although many systems do not give you this option , for example online banking systems do not give you the option to continue, they simply timeout and inform you that you have been logged out.