I’m not that good at animating, but see if this works for you:
$w.onReady(function () {
const myArray = ["Review1", "Review2", "Review3", "Review4"]
let index = 0
let random = myArray[index++ % myArray.length]
$w("#textField").text = random
setInterval(async function () {
await $w("#textField").show("slide", { duration: 500 })
$w("#textField")
.hide("slide", { delay: 19800, duration: 500 })
.then(() => {
random = myArray[index++ % myArray.length]
$w("#textField").text = random
})
}, 20000)
})