A link near the top right of the page? Might be a navigation bar entry. Go the your application's Shared Components and look for the "Navigation Bar Entries" link to manage them.
Indeed, there was that link...thank you for your help!
Another question...is there any pop-up feature for APEX?
For example if I will like to reject a request in a form, after a hit Reject button, I would like to pop-up a "Justify" item that must be filled and then after submit, to update same row in that table with the Justify comment...
Search the forum's posts for what you are trying to do. This is a common question here and has been answered several times. Look into a plugin that may help you accomplish your goal.
If you get stuck create an example on apex.oracle.com and post a new thread with your workspace credentials and a good description of what you have tried.