transfer of unused voucher

I previously activated a voucher but have not yet registered for a course with it. The course I intend to select is an online training organized from Paris between July 15-18, 2025 (FortiSOAR Design and Development 7.3). However, I will not be attending; instead, my new colleague, who has also registered on the platform, will take my place. How can I transfer the voucher rights to him and remove its usability from my account?"