Reading data from BLE device with web bluetooth?

I'm new to javascript so i might have some unconventional way of programming. That said, I'm working on a project where I need to read and write data to a custom BLE device. I'm using the gatt server protocol for the connection. I'm able to make a connection with the device but now i'm trying to read data from the registers.

I looked trough the web samples from google as well as the web bluetooth github but I cant make any sense of it. The code below is my current attempt to break this. earlier tries had me get stuck on the fact that the value that I got was an object or a promise object.

function readFromPcb() {
    let p2 = new Promise((resolve, reject) => {
        if (device.connected === false) {
            reject('network Error');
        }
    })
        .then(characteristic => {
            readValue = characteristic.readValue();
            console.log('data is: ' + readValue);
        })
        .catch(error => {
            console.log('error: ' + error + DOMException.name);
        });
}