const clientData = JSON.stringify({
    challenge: base64url.encode(Buffer.from(publicKeyCreationOptions.challenge as ArrayBuffer)),
    hashAlgorithm: 'SHA-256',
    origin,
    type: 'webauthn.create',
});

const keyParams: EcdsaParams = { name: 'ECDSA', hash: 'SHA-256' };
const signature = await window.crypto.subtle.sign(
    keyParams,
    keyPair.privateKey,
    new TextEncoder().encode(clientData),
);