The webpage isn’t loading that slow, it simply does not have content that qualifies as LCP and therefore the Performance test part of lighthouse fails.
There are many reasons on why this might be happening, but it all originates in the way the webpage is coded.
I would search google for Largest Contentful Paint Error Lighthouse Report or Lighthouse failing with NO_LCP error for instance and see how others are solving it, or contact your provider glideapps.com directly.