enabling HTML in post "header"

Hi all,

I have a featured post slider with images on my homepage, and I would like to have the post title link directly to another page in my site, instead of an expanded version of the post. Another topic on this forum from a couple of years back suggested using a plugin that enables optional post headers, which replace the titles, and can have links attached to them. I found the appropriate plugin, but the now header option says “HTML disabled” and I can’t find how to enable it, which I take would then allow me to insert a direct link?

Thanks for your help!