First, we run Ngrok with the following command in another Terminal instance: ./ngrok http 5000. Once Ngrok is running, the app provides a unique URL for our local web server, such as https://27195c65.ngrok.io. Now that we have a URL, we simply need to configure Twilio to use it. In the Twilio Console for our phone number there’s a place to add the custom URL and then save the configuration.
A general voicemail greeting is what callers will be greeted with if you are unable to answer the phone at work. It is the everyday greeting, used as the default, unless you have set up a temporary greeting, such as an away message while you're on vacation, or a special message during a holiday.

When the Voicemail section expands, click the Voicemail Greetings link, at the bottom of the section Fig. 3 Click to view ; When the Voicemail Greetings window opens, you can set your Busy and/or No-Answer greetings to the default System greeting or a pre-recorded personal greeting. For Busy Greeting, make sure Personal Greeting is selected
Most people screen their phone calls and often avoid answering unknown numbers. If you’re applying for new positions, you should try to view each unexpected call as an exciting opportunity! In the event that you simply can’t pick up the phone, you’ll want a polished voicemail greeting to let the caller know they’ve reached the right person.