How can I make a JavaScript class wait for a specific key to be pressed before continuing?

What I’m trying to do is to wait until the correct key is pressed for it to continue

The code i’ve done so far is this:

class exampleClass {
    async waitForKeyPress() {
        return new Promise((resolve) => {
        
            const listener = (e) => {
                document.body.removeEventListener("keydown", listener);
                if(e.key == "z") {resolve(); alert("e");}
                else {
                    this.waitForKeyPress();
                }
            }
            document.body.addEventListener("keydown", listener);
        });
    }

    async doStuff() {
        await this.waitForKeyPress();
        console.log("correct key pressed");
        //do stuff
    }
}

let exampleObject = new exampleClass();
exampleObject.doStuff();

This doesn’t work for me since if I press a different key then it doesn’t detect that the z key is pressed for some reason
The part that is confusing for me is is that if you do

async function waitForKeyPress() {
        return new Promise((resolve) => {
        
            const listener = (e) => {
                document.body.removeEventListener("keydown", listener);
                if(e.key == "z") resolve();
                else {
                    this.waitForKeyPress();
                }
            }
            document.body.addEventListener("keydown", listener);
        });
    }

    async function doStuff() {
        await this.waitForKeyPress();
        console.log("correct key pressed");
        //do stuff
    }

    doStuff();

it works, the only difference is that it’s not in a class. However, I would like it to be in a class

>Solution :

Remove listener only when z is pressed instead of removing it prematurely.

class exampleClass {
    async waitForKeyPress() {
        return new Promise((resolve) => {
            const listener = (e) => {
                if(e.key === "z") {
                    window.removeEventListener("keydown", listener);
                    resolve();
                }
            }
            window.addEventListener("keydown", listener);
        });
    }

    async doStuff() {
        await this.waitForKeyPress();
        console.log("correct key pressed");
        //do stuff
    }
}

let exampleObject = new exampleClass();
exampleObject.doStuff();

Without promise,

class exampleClass {
    constructor() {
        // the reason for this line is because "this"
        // inside doStuff will be window instead of
        // the class itself.
        this.doStuff = this.doStuff.bind(this)
        window.addEventListener("keydown", this.doStuff);
    }
    
    doStuff(e) {
        if(e.key !== 'z') return
        window.removeEventListener("keydown", this.doStuff)
        console.log("correct key pressed");
        //do stuff
    }
}

let exampleObject = new exampleClass();