makecred.rp.icon.png.js

var randomChallengeBuffer = new Uint8Array(32);
window.crypto.getRandomValues(randomChallengeBuffer);

var base64id = 'MIIBkzCCATigAwIBAjCCAZMwggE4oAMCAQIwggGTMII='
var idBuffer = Uint8Array.from(window.atob(base64id), c=>c.charCodeAt(0))

var publicKey = {
    challenge: randomChallengeBuffer,

    rp: {
        name: 'FIDO Example Corporation',
        icon: 'https://fidoalliance.co.nz/testimages/catimage.png'
    },

    user: {
        id: idBuffer,
        name: "alice@example.com",
        displayName: "Alice von Wunderland",
        icon: 'https://fidoalliance.co.nz/testimages/catimage.png'
    },

    attestation: 'direct',
    authenticatorSelection: {
        'authenticatorAttachment': 'platform'
    },

    pubKeyCredParams: [
        { type: 'public-key',  alg: -7  }, // ES256
        { type: 'public-key', alg: -257 }  // RS256
    ]
}

navigator.credentials.create({ publicKey })
    .then((newCredentialInfo) => {
        console.log('SUCCESS', newCredentialInfo)
    })
    .catch((error) => {
        console.log('FAIL', error)
    })