HI,
I am new to dropbox api . Trying to start with java documentation for auth but documentation is so confusing. I found that https://api.dropboxapi.com/oauth2/token should be used but on https://dropbox.github.io/dropbox-api-v2-explorer there is no way to try or on https://www.dropbox.com/developers/documentation/http/documentation It is not on listing too.
@suzuka pcworld is correct, it is listed there, just not in the sidebar. Here's the direct link for the OAuth 2 documentation. The OAuth guide may also be useful.
Also, the "Get Token" button on the API Explorer does use the OAuth 2 "token" flow.
In any case though, if you're using Java, we recommend using the official Dropbox API v2 Java SDK, which will do most of this work for you. For example, you can see how the app authorization flow is implemented in this example.
Just search for "/oauth2/authorize" in https://www.dropbox.com/developers/documentation/http/documentation, it's there, it's just missing from the table of contents.