Hi Jeewani,
It is difficult to say exactly why this occurs as I am not able to see which URLs you are talking about. The link you posted looks to redirect back to the CMS for the same site but if you are unsure if you are going back to the correct admin, you can visit the administration directly (typically https://yoursite.com/admin unless this has been changed by your administrators). After logging in there, you should be able to enter the License keys application and add the license for your domain (Manage site licenses). You can get your license keys from the Kentico Client Portal and if you need a guide on how to use this portal, you can find one here: Client Portal Guide
Otherwise, I would check with your site administrators/IT department to have them check on why this is being redirected. I hope this helps!