Hi andrzej,
Thank you for contacting the Microsoft Community.
We understand the importance of completing the Microsoft Security Virtual Training Day: Security, Compliance, and Identity Fundamentals 1, let me assist you with the link of your event.
Based on the information you have provided, it is advisable to send an email through techskillssupport@microsoft.com directly to further assistance with regards your appointment to the event as they are the only one who have an access with the training inquiries.
If this solves your problem, please indicate “Yes” to the question and the thread will automatically be closed and locked. In case we do not receive a response, the thread will be closed and locked after one business day. If the resolution provided did not resolve the issue, please post a new question.