And if you find that you mute your phone accidentally, you need to unmute it then you can hear the sound. 1. For iPhone users, they can go to check whether the Ring/Silent switch is turned on. If the switch shows orange, that means your phone is in the silent mode so you need to toggle the button to turn on the Ring mode.
When you're in a call, wait for the Add Call button to light up, so you can add a third caller via 3-way calling. Tell the other person to wait, click the button, and call yourself. Stay on the line and listen to your own voice mail greeting, then for the tone that indicates recording has begun. Tap Merge Calls. All three calls are merged—and the third one (your voice mail) is taping the other two.

Thank you, US Mobile team. I had issues with voice mail on my new phone and you persisted until we finally got it resolved. It turned out to be erroneous numbers in the “Call Forwarding” settings. You were courteous and called me to work on it when that became more efficient than our emailing. Very good service.
There are two steps you have to do before you can use voicemail on your phone. The first is that you have to add a voicemail number. This number varies by country and also your service provider. If you’e use AT&T, you can follow AT&T Galaxy S21 voicemail setting. Open the “Phone” app. Tap the 3 dots on the top right. Tap “Settings“. Tap “Voicemail“. Tap “Voicemail Settings“. Take note of the green number below “Voicemail number“. Go back to the dialer and enter the number from Step 6 (including the *). Press the green phone button. The voicemail number has been set. Return to the Start screen.