How to uninstall an app when "Uninstall" dialog is not shown? How to uninstall this app where after clicking uninstall, only the picture of the app shows up and there's no "OK, cancel" prompt? 

My device is Asus Zenfone 2 Laser 5.5 (ZE550KL).
Boot into safe-mode, go into Settings → Applications/Apps → find your app and uninstall it. This would work unless your device is a system app.
If it is a system app, disable it from Settings app. If you don't get the option to disable it, and you're certain that disabling it would not affect the stability of your Android (think of boot loops and crashes), then enable usb-debugging, setup adb, and issue either of these commands:

adb shell pm disable-user PACKAGE_NAME         # disables the app         
adb shell pm uninstall --user 0 PACKAGE_NAME   # uninstalls the app for primary user account

Replace PACKAGE_NAME with the package name of the troublesome app. To  get help in finding it, see my answer here.