First  turn off "Enable  zDLT Automint" in the desktop wallet under settings, otherwise it will always automint 10% of your coins.
If you go to the privacy tab and then on the bottom you can put in the amount you want to send. Leave the receiving adress empy and it will automatically send it to one of your adresses.
There might still be an error saying "Try to spend with a higher security level to include more coins", but the team is working on fixing this error.