Hi there,
if you run a GTMetrix report on the site, and check the waterfall report you will see what is affecting the FCP timing. Each request to your server has a high requesting/waiting time in comparison to requests being made to 3rd party servers such as google – that is something your host should be able to help with.
Any improvements made to FCP will trickle down to LCP.
The other issue for the high LCP time is you’re using a lazy loader, if you check the page speed insight report it tells you what the LCP Element is – which is the first featured image – this being lazy loaded means it gets loaded after all other requests are complete. You may want to check with the lazy loader plugin developer if there is a way to exclude above the fold images.