JavaScript: How to rewrite code to use dynamic values instead of hard-coded ones?

Question

I have following JavaScript function as code snippet:

window.registerWebAuthn = function () {
            const publicKeyCredentialCreationOptions = {
                challenge: new Uint8Array(26),
                 rp: {
                    name: "Example",
                    id  : "localhost"
            },
                user: {
                    id: new Uint8Array(26),
                    name: "[email protected]",
                    displayName: "Foo Bar"
                }
            };

The string values for the following parameters are hard-coded:

• id
• name
• displayName

I want to rewrite this code to use dynamic values.

Can you tell me how I can do that?