I am having a music platform website where at a time 20 songs are visible right now then after scroll the other 20 are visible. So how can I confirm whether the songs which are coming after scrolling are crawled and then indexed by Google or not?
You can check if text is indexed by searching for it on Google. For example here is a song that was visible after scrolling:
Google easily finds that on your site. Google probably isn't using infinite scroll to find it. It looks like you link to it in multiple places including user profile pages and music category pages. When your content is linked from many places, you don't have to worry about Google getting to everything from the home page.