After creating, the Voicemail Greeting, you can test it by calling to your number from another phone, and see if it is playing correctly or not. Open the Phone App. On the lower screen, tap on the Voicemail option. Select Custom, with this option, you can record the personal voicemail greeting on the iPhone. Tap Record, to start recording the voicemail greeting message on the iPhone. Greeting samples are given in this article below, Once you are done with recording, tap Play to listen. Lastly, if everything is alright, and custom voicemail recording is perfect, then tap Save.
15. “Hello, you’ve reached the Sales Department at [Company name]. All of our representatives are currently helping clients [insert goal such as, ‘achieve 40% growth through streamlining HR’] and are unable to take your call. Instead of putting you on hold and taking up your valuable time, please leave your name, company, and phone number and we’ll give you a call back ASAP. Thank you!”

Even in today's fast-paced world, customers don't like being greeted with an automated message. According to the New York Times, callers of a certain age are put off entirely if they are answered by a voicemail instead of a real person.
Website: https://www.amazingvoice.com/blog/10-best-professional-voicemail-greetings