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?
Website: https://community.verizon.com/t5/My-Verizon/How-do-I-change-my-voicemail-to-the-automated-greeting/td-p/1047569

Whether you are setting up voicemail for the first time or creating a unique voicemail greeting on your Samsung S20 or S20Plus, our brief guide will walk you through the process step by step.
Method 1 of 2: Deactivating Your Voicemail Manually Access your Voicemail settings. Some phones offer an option to turn off your voicemail via the settings. Deactivate your Voicemail via settings. If you're lucky, your phone will come with an option to deactivate your voicemail service. Input a phone code. ... Test to ensure your voicemail is deactivated. ...