However, some cellular service providers allow users to access and update their voicemail by calling their own numbers from working landlines or phones on other wireless networks, so users whose accounts include such an option and who have access to alternative service could keep the voicemail greetings updated even when their own mobile phones cannot connect to cellular or internet service.
To set up a personal voicemail greeting on a Galaxy S10, open its Phone app and call your voicemail, then tap "3" to enter the settings.

Step 1: On your iPhone, go to Settings >Phone. Step 2: Tap the Change Voicemail Password option.Step 3: Enter a new voicemail password, then tap Done. Step5: Re-enter your new voicemail password to confirm, and tapDone. How do I set up my voicemail on my iPhone? From a Home screen, navigate: Phone app > Voicemail(lower-right). Tap Set Up Now. Enter a password then tap Done. Re-enter the password then tap Done. Tap Custom to record a greeting. Tap Record to begin. When finished, tap Stop. To complete, tap 'Done' or 'Save'. Call the Voicemail box: Press *86 (*VM) then the Send key.Press and hold number 1 to use the voicemail speed dial. If callingfrom another number, dial the 10-digit mobile phone number thenpress # to interrupt the greeting. Follow the prompts to enter your password and retrieve yourmessages. Where do voice messages save on iPhone?
Tap the three dots (upper right corner of screen)Tap “settings”Tap “voicemail”Tap “advanced settings”Tap “setup.Tap “voicemail number.Enter your 10-digit phone number and Tap “OK.Tap the home key to return to the main menu.