Hello, @Niddy,
Yes, you can add a custom block underneath the product images on the Single product page. I have captured a video for you on my test site. Please watch it complete and follow the steps shown in the video: https://www.veed.io/view/2de2d045-5a33-40c3-abe9-1ccb2a38a8f3?sharingWidget=true&panel=share
Regards 8Themes Team.