I am trying to get the refresh token by using the request url https://api.dropboxapi.com/oauth2/token.
It shows 404 not found with below outputs. I was wondering if any suggestions could be provided to fix this.
You can find information and examples of using that endpoint in the documentation here. This blog post may be useful as well. Make sure you're calling it correctly as shown. I just tried it and it is working for me.
If something isn't working as expected for you, please share the relevant code snippet(s) and steps to reproduce the issue so we can look into it.