Strange it was a robo call but they hung up before the robo could finish explaining what they were trying to verify. Tried calling it back and it went into an automated message that was not clear as to what or who they are.
This number called, but, left no message. Here's what the female robotic voice says when I called the number back: "Thanks for the call. Configure your number's voice URL to change this message. Let us know if we can help you in any way during your development". Then, they just hang up. Weird.