LTAP (Leaving to avoid punishemen) is a 3 day ban so you could wait it out, or you could try make an appeal on the ban appeals page which ill link below for you. But basically you was banned for leaving during the process of a staff sit in which you awaited some form of jail/mute punishment.
Explain your case and be honest as possible, if you make a good appeal and the staff team things you're honest, your appeal will be successful and you will be unbanned.
https://cloud-gaming.co.uk/forum/index.php?/forum/8-ban-appeals/
though it's not guaranteed you will find success in appeals. If that is the case, learn from what has happened accidental or deserved and work to make sure it doesn't happen again.
I see you appealed and it was denied, so at this stage you'll just have to wait it out, but atleast now you know your wrongs.
https://cloud-gaming.co.uk/darkrp/rules.php
Highly Recommended you read through this, a few times it will save you a lot of trouble and helps everyone out too.