Custom javascript to flash images from a github directory for a set time and then auto advance

Try this JS:

Qualtrics.SurveyEngine.addOnload(function () {
	this.hideNextButton();
});
Qualtrics.SurveyEngine.addOnReady(function () {
	const quest = this;
	const qc = quest.getQuestionContainer();

	//Add links to images here
	const imgLinks = [
		"https://iima.au1.qualtrics.com/ControlPanel/Graphic.php?IM=IM_cCQ21dgfJJU1JDT",
		"https://iima.au1.qualtrics.com/ControlPanel/Graphic.php?IM=IM_03uFE9bjTVeXlad",
		"https://iima.au1.qualtrics.com/ControlPanel/Graphic.php?IM=IM_9LTvOOtrgXEorQh",
		"https://iima.au1.qualtrics.com/ControlPanel/Graphic.php?IM=IM_9z9n5amvozfILqZ",
		"https://iima.au1.qualtrics.com/ControlPanel/Graphic.php?IM=IM_0jH3QAOZh6Av7Dv"
	];

	// How many images do you want to show?
	const numImages = 2;

	// Duration of the flash in ms
	const flashTime = 200;

	const images = [];

	for (let i = 0; i < numImages; i++) {
		const random = Math.floor(Math.random() * imgLinks.length);
		const img = imgLinks.splice(random, 1).pop();
		images.push(img);
	}

	const imageHTMLs = images.map((url, index) => {
		const html = '<div id="img_' + index + '" style="text-align: center;opacity:0"><img src="' + url + '" width="80%" style="margin: auto" /></div>';
		return html;
	});

	imageHTMLs.forEach((item) => {
		qc.insertAdjacentHTML("beforeend", item);
	});

	const allImages = Array.from(qc.querySelectorAll("img"));
	allImages.forEach((item) => {
		item.style.display = "none";
		item.parentElement.style.opacity = 1;
	});

	setTimeout(() => {
		const startTime = Date.now();
		for (let i = 0; i < allImages.length; i++) {
			const image = allImages[i];
			setTimeout(() => {
				image.style.display = "";
			}, i * flashTime);
			setTimeout(() => {
				image.style.display = "none";
			}, flashTime + i * flashTime);
		}
		setTimeout(() => {
			quest.clickNextButton();
		}, flashTime + allImages.length * flashTime);
	}, 500);
});

Demo: https://iima.au1.qualtrics.com/jfe/preview/previewId/00a1841e-33a5-49ae-a9c5-6934da853af4/SV_8HBDY4VRJnFn40J/BL_7OMuuVVOdTtgmma?Q_SurveyVersionID=current