As a manager, click on the "Prioritize requests" tab and search for the employee you wish to manage the training request for.
Then add a comment to justify the refusal. The request will be archived and visible in "Archives". An email will be sent to the employee concerned.
It is also possible to follow this procedure from the “Others” tab, which allows you to view and act on requests to be prioritized from employees who do not report directly (the display of this tab will depend on the rights activated when the roles were set up).