on the top right, of your pull down control panel, is the hamburger button, it looks like three dots vertically. be sure to pull the menu down all the way it won't be here unless the menu is completely open with all the options on that page showing. push the hamburger button and you'll get the option button order is the first one most likely, hit it and you'll see grayed out buttons on the top, these are buttons that can be added to your quick commands panel should you choose. I always checking this after updates because Samsung likes to reorder your buttons. if your phone has Wi-Fi calling which is a special feature I have an unlocked note which works on all carriers and there is no Wi-Fi calling, but if you have a carrier phone and pay for it it should be there and you should be able to pick it click it hold and drag it down to the menu and add it to your button list wherever you'd like. you can also use this to change the order of your buttons if you like. I personally must change this order or I go crazy. I need my Wi-Fi mobile data flashlights and sound as my first options. because I change these most frequently this is a cool personalization feature you only get on Android Apple people they know not. hope this helps it's not hard at all. Have a good day
