This is my js for generating the random images:
var images = ["Image+1", "Image+2", "Image+3"];
var random = images[Math.floor(Math.random() * images.length)];
var url = "https://dummyimage.com/250x150/000/fff.jpg&text=" + randomPick;
Link to my codepen: https://codepen.io/luca099/pen/RwRabQv