PWA app android package build issue

hi team, we are trying to build pwa app using pwabuilder website for android platform. we are hosted app with Https and deployments are handled using kubernetes. app is successfully getting build for IOS but getting following issues on for Android packaging -

“unable to verify the first certificate code: UNABLE_TO_VERIFY_LEAF_SIGNATURE”

looking forward for immediate help on this.

what certificate is this referring to?

what makes the certificate invalid?

do you build separately for ios and android? wasn’t it a web app?