Hello,
This approximates when the main content of the page is visible to users, thus the site needs to be optimized in general so that the largest content element is displayed more quickly.
https://developer.chrome.com/docs/lighthouse/performance/lighthouse-largest-contentful-paint/?utm_source=lighthouse&utm_medium=lr
If we check your site via Insights, we can see other issues: which together can cause this problem. So I suggest you sort out these diagnostic issues ( and then re-check whether the “Largest contentful…” issue persists or not.
https://ibb.co/VH99q4q
Best Regards.