Great question! DIGITS is only for T-Mobile numbers so it will only work if the number is on your T-Mobile account. In your case, the number is owned by Verizon so it cannot be used with DIGITS.
You can check with your employer to see if they would allow you to port that line to us, then you could use that line in tandem with your personal line on your iPhone 7.
This thread was the product of our fantastic collaborators during DIGITS Beta! As many terms have changed and bugs have been exterminated since the Beta launched, the information here may no longer be accurate. If you still have a question, please search our active threads or ask a new question in the DIGITS space!