Unfotunately not on my index page.
But what is weird is that on another page, I managed to add it by putting the “head code” in a html box at the top of my page with and the code further down the page (see result here challenge Double Ton Impact)
On my index page, I gave up and added the “newsletter” code instead. Not as pretty and only one testimonial, but it works https://rapidely.app/
Hope it helps, and if you find another way, would love to hear about it.