Sitecore Indexing manager is not showing indexes

My old instance was using solr-5.5.1, I was able to connect using http://localhost:8983/solr. However I installed solr-6.6.2 for my new instance and I could not connect to it over http that is the reason indexes were not appearing in Indexing Manager.

I planned to configure solr connection over https using ssl certificate.

I followed below url to generate and install local ssl certificate for solr – https://gist.github.com/kamsar/c3c8322c1ec40eac64c7dd546e5124de.

Things to be taken care while following above url-

1. Add path of keystore to environment variable. Added “C:\Program Files\Java\jre1.8.0_261\bin” to Path variable.
2. Check and confirm path of solr-ssl.keystore.jks file in your machine – .\solrssl.ps1 -keystoreFile C:\solr\solr-6.6.2\server\etc\solr-ssl.keystore.jks

Still solr is not accessible with http://localhost:8983/solr, however after certification installation and using https://localhost:8983/solr , indexing manager start showing indexes.