Hello @Juan Mesa Sierra Thank you for posting your question on Microsoft Q&A platform. Sorry for the inconvenience this must have caused you!
I understand that you are trying to install the agent and it errors as "Agent you are trying to install/upgrade is not built for , can not be installed on this Operating System."
Based on the error message, it appears that the operating system is not supported by Azure Migrate. You can refer to the support matrix page here - https://learn.microsoft.com/en-us/azure/migrate/migrate-support-matrix
If you are migrating an AWS VM/Server, you can follow the guide here - https://learn.microsoft.com/en-us/azure/migrate/tutorial-migrate-aws-virtual-machines
Note: Ensure that the OS and the kernel version is supported.
Hope this helps!