@TEnnis I am not a 8x8 expert but it seems that this is not possible what you are trying to achieve with their current app available in the app directory. You should confirm this with your 8x8 representative.
If you get confirmation that this is not possible, know that other phone system, like Aircall is giving you the opportunity to do what you want to achieve out of the box.
Don’t forget to mark my reply as a solution if you are satisfied. If not, do not hesitate to ask me anything!