Website: https://saraharpminter.org/answer/pre-recorded-answering-machine-messages
Great question! Although I don’t know if there is a specific function for this on your particular phone, the best way to save the message is the simplest. Turn up the sound as high as you can and record it onto a digital recorder (like you would use for a lecture), a cassette recorder or your cell phone if you have a voice recorder on it. Then save it as an MP3 on to your computer for safe keeping. You can also Google your vtech model number to see if you can find an owner’s manual. They might have a way to save a recording in there. Probably not, but it’s worth a shot.

Open Phone → Make sure you are on Keypad → Press and hold the number 1 for a few seconds. It will call your voicemail; You can check your voicemails here. 3. Force close and reopen the Phone app. To force close Phone, on iPhone X and later swipe up until you see the apps in task view, then swipe up again on Phone.
Finally, and most annoyingly, getting set up with On Voicefeed was pretty tedious. You have to enter basic information, just like almost any other app, which is fine. But then you’re asked to enter a security code that is sent to you by text. At this point, I’m thinking, “Alright, but this better be it.” Then, the app asked me to call a number that was automatically added to my contacts in order to activate the account. Fortunately, that was the end of it, but I was still a little peeved at how long it took to get started. I’m sure that some of those steps are necessary to tap into your voicemail, but finding a way to streamline the process would be much appreciated.