Windows server 2019 is not supported yet for IMC. But the process is to backup the data using the IMC admin client, then build an identical version & patch stack on your new server, the restore the database.
Then install any additional updates that are pending beyond your existing installation. You can only restore like to like
After it all looks good you will need to transfer the license from the old server to the new. There is an online page to do this.
Other posts in this forum have additional details.
Neil