Wi-Fi Calling is not supported on the Samsung S21 because it does not have a rear-facing camera.

Wi-Fi Calling is not currently supported on your device.

If you have a Samsung Galaxy S21, you can get Wi-Fi Calling by following these steps:
From your home screen, open the Settings app.
Under Wireless & Networks, tap Mobile networks.
Tap Wi-Fi Calling.
Under Use Wi-Fi Calling, select On.
Enter your phone number and password to enable Wi-Fi Calling.

Galaxy S21 does not have Wi-Fi Calling.

Yes, the S21 does have Wi-Fi Calling.

There are a few ways to force your phone to Wi-Fi call. One is to go into your Phone Settings and turn on Wi-Fi Calling. Another way is to go into your Phone Settings and turn on Airplane Mode.

Wi-Fi calling is not supported on Samsung devices running Android 9.0 or later.

There are a few things that could be causing your Samsung not to connect to Wi-Fi. First, make sure that the Samsung is in range of the Wi-Fi network. If you’re using a wireless router, make sure that it’s turned on and connected to the internet. If you’re using a wired connection, make sure that the Samsung is plugged into an outlet and that the cable is connected to the Samsung’s Ethernet port.

There could be a few reasons why your S21 is not receiving calls. One possibility is that the S21 may not have been set up to receive calls. You can check to see if your S21 is receiving calls by following these steps:
From your device’s home screen, tap the Settings icon.
Under “Phone,” tap Call settings.

There are a few ways to force a Wi-Fi call on your Samsung phone. The easiest way is to go to the Phone menu and select Call. Then, under Calling Options, select Wi-Fi Calling. You can also access this option by pressing and holding the phone’s power button until it goes off, then pressing it again to turn it back on.

To enable Wi-Fi calling on your Samsung, follow these steps:
Open the Settings app on your phone.
Under Wireless & Networks, tap Mobile Networks.
Tap Wi-Fi Calling and turn it on.
Enter your mobile number and password to connect to the network.
You’re all set!

There are a few different ways to fix Wi-Fi calling on Android. You can try to reset your phone, clear your cache and data, or uninstall and reinstall the app.

To enable Wi-Fi calling on your Samsung A12, follow these steps:
From your home screen, open the Settings app.
Under Wireless & networks, tap Mobile networks.
Tap Wi-Fi Calling and turn it on.
Under Advanced settings, make sure Enable Wi-Fi calling is set to On.

On the Samsung Galaxy S10, go to Settings > System > Phone > Wi-Fi Calling and toggle on the switch.

To enable Wi-Fi calling on your Android device, open the Settings app and select “Phone” from the main menu. Under “Phone Options,” select “Wi-Fi Calling.” You’ll need to enter your phone number and password to activate Wi-Fi calling.