Sorry for the delay
We are experiencing tropical storms here and our electric has been off
Also the code needs to go into the element content bit not the header (thats for background inages & css)
So select the image (s)
give it an additional class name (EG link1) Give the image ALT a meaningfull title
over to the elemnt tab
insert the following code as is (of your choice dependinbg on either a page or external link
NB if its a page link DON'T FORGET THE .html suffix
this for a page link
<a href="about-us.html" class="link1"> <picture>
<img alt="Image Title" src="./image-folder/image-name.xxx" loading="lazy">
</picture>
</a>
This for an external link
<a href="DestinationURL.xxx" class="link1"> <picture>
<img alt="Image Title" ./image-folder/image-name.xxx" loading="lazy">
</picture>
</a>
There is a bit of a fiddle if you struggle with the code etc, I can do a short 'HOW TO" video if required