Server Requirement In Ionic-Adafruit Arduino project

Hello all! I am currently building a Ionic app that communicates (Bluetooth) with a Arduino Uno to change the light settings and functions on a Adafruit ring light based on the user input on the app. However, I’ve ran into a bit of a obstacle.

So far, despite having functions in my javascript and using a Bluetooth terminal app to connect to the Arduino Bluetooth from my phone, I have been unable to send the data gathered from the slider to the Arduino successfully. I talked to a few friends about it, and nobody seem to be sure what the problem is but suggested I may need a server. I am unfamiliar with the functionality of a server, or even how to set up on, in relation to this project. I was certain that all I had to do was connect and send data.

So, my question is, would a server be required in this type of communication? How would I set this up, and what role would it play?