LCP is actually based on the size of the element in pixels.
On the ryrob site the H1 doesn’t take up as many pixels as his disclaimer paragraph.
So writing a longer paragraph in a larger font nearer to the top of your site should make it the LCP – instead of the H1 or the image as is the case in your site.
I would not focus on the LCP.
Look at what can be done to optimize the site and improve its overall performance.
Run a test on GT Metrix to see which requests are taking the longest time.