If you hold a perpetual AppMon & UEM license, you can continue running it unsupported. This is not recommended due to the lack of fixes and security patches! For that purpose, we will continue providing access to your product license (contact firstname.lastname@example.org) and the software.
However, it wouldn't be possible to open support tickets after March 31, 2021, except you have extended or premium support. For further questions, please look at the FAQ or post your question in the Open Q&A community.