Context does matter here. If the caller would reasonably expect you to answer the phone (such as if they were calling a store or other place of business), an apology for not being able to get to the phone makes the most sense.
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.

The primary purpose of voicemail greeting is to inform your caller that you are not available and ask to leave the message.
There's no single best way to craft an after hours greeting. The most important point is that you equip your customers with what they need to know, and give them an avenue to contact you, whether that's through voicemail, email, or other channels.