<input type="text" id="input">
<script>
    const testAssertionMessageBase64 =
        "AKMBomJpZFhAKAitzuj+Tslzelf3/vZwIGtDQNgoKeFd5oEieYzhyzA65saf0tK2" +
        "w/mooa7tQtGgDdwZIjOhjcuZ0pQ1ajoE4GR0eXBlanB1YmxpYy1rZXkCWCVGzH+5" +
        "Z51VstuQkuHI2eXh0Ct1gPC0gSx3CWLh5I9a2AEAAABQA1hHMEUCIQCSFTuuBWgB" +
        "4/F0VB7DlUVM09IHPmxe1MzHUwRoCRZbCAIgGKov6xoAx2MEf6/6qNs8OutzhP2C" +
        "QoJ1L7Fe64G9uBc=";
    if (window.internals) {
        internals.setMockWebAuthenticationConfiguration({ hid: { payloadBase64: [testAssertionMessageBase64] } });
        internals.withUserGesture(() => { input.focus(); });
    }

    const options = {
        publicKey: {
            challenge: new Uint8Array(16),
            timeout: 100
        }
    };

    navigator.credentials.get(options).then(credential => {
        // console.log("Succeeded!");
        window.webkit.messageHandlers.testHandler.postMessage("Succeeded!");
    }, error => {
        // console.log(error.message);
        window.webkit.messageHandlers.testHandler.postMessage(error.message);
    });
</script>