There are primarily 2 ways on the app to check in a guests. The 3rd way is more tedious and is not advised unless you are making edits as well.
The main function of the app would be to scan guests in at the entrance. So Using the camera would be the fastest way as you would not have to manually find the guest and scan them. To find out how to scan a guest in through the camera, please follow this link: https://www.2iins.com/faq/how-do-i-scan-the-code/
You can easily check in a guest by selecting a guest and clicking on check in/Out Guest
The last way to edit a guest is to go in by clicking View/Edit Guest button and manually pressing the button check-in inside. We don’t generally recommend checking in guest this way as it is the most time consuming method.