Android phones can access voicemail by holding down the 1 key on the dial pad until the phone dials your 10-digit phone number. You will automatically connect to your mailbox and be prompted to enter your temporary password; this password is the last 4 digits of your phone number followed by the # key. Start the Google Voice app. Tap the three horizontal lines at the top left of the screen (sometimes called a hamburger menu), and then tap “Settings.” In the Voicemail section, tap “Voicemail greeting.” Tap “Record a greeting.” How do I access my voicemail? To call your voicemail on an Android phone, simply open your phone’s dial pad and hold your finger down on the “1” key. You can also call your voicemail from a different phone by calling your own number and tapping the pound key. How do you check your voicemail?
There is a way to save a voice message on iOS mobile by recording it on Notes or Voice Memos and set them as voicemail greeting. Also, you can share them using SMS, Email, Airdrop, Google Drive, and more, to make a back-up of the recorded voicemail. It isn't delightful when you expect a client call and can't answer it at the moment. You can't get all your phone calls at all times, especially when you are busy with your work. That is why it is important to record voicemails on your iOS device and set it as a response on an incoming call. Therefore, we have listed the steps below on how to capture voicemails on iOS.

Procedure to set up voicemail on iPhone 11. You have to create a passcode before you can use your voice mail messaging services The voice mail service provided by the carrier will already be stored in your device. On your iPhone open the phone app. Tap Voicemail present in the bottom right corner of the screen. Select that up now.
In case you are not connected on the Internet & need to check your Voicemail box, you always have the option to call the standard voicemail number free wherever you are in the world. More information here.