Website displays iframe tag when opened

I get the following message when I try to open a website - <iframe src="https://f64-image-analyst.vercel.app" title="f.64 Image Analyst" loading="eager" allowfullscreen>

I was had the webpage open and did a "Shift+cmd+F" to make full screen, when I closed it and went back to the webpage got this message - <iframe src="https://f64-image-analyst.vercel.app" title="f.64 Image Analyst" loading="eager" allowfullscreen>

How do i get the webpage back, I have tried closing the f64.com website which includes the like to a web tool Analyst

I have restarted my iMac

Nothing works,

Need some help

Michael