I need templates used for these portals,
Is it open-source and available somewhere as I am interested to deploy a replica of it with customized branding for one of my clients.
I have gone through https://github.com/blockchain-certificates/blockcerts-verifier but it has a different structure, I am unable to find the exact template.
Both examples that you’ve highlighted are commercial pages provided by Learning Machine to a customer. We’ve embedded the open source verifier into a simple web page. Feel free to do the same! Blockcerts doesn’t provide design templates for this, since each project’s need may be unique.