Hi Akansha, the sole purpose of the Lighthouse is to highlight the pain in the application. If your page is taking longer to load, you should trace the reason for slow loading rather than bribing Lighthouse for better results.
But, if you really want to do so, check lighthouse configurations and pass the configuration object to the lighthouse scan. I do not have the exact configuration for this use case. you can always check out the official lighthouse documentation here: https://github.com/GoogleChrome/lighthouse/blob/master/docs/configuration.md
Let us updated, if you find out a solution. :)