You already know it: On February 2nd, 2021 the sale of new Atlassian Server licenses ended. Ever since server products have not been further developed. On February 15, 2024, the support for all server products will end.
These and numerous other questions are probably buzzing around in your head. No worries, we got you covered with everything you need to know about Atlassian Server end of life.
You are not alone during this change. We will faithfully and actively support you with our many years of experience!