demodocsroot=./data/skins/evolution
docsroot=./data/skins/evolution
You need to address some rules in Directadmin.conf to evolution.
Then it works (maybe hit shift+F5 in your browser once).
Version: DirectAdmin v.1.57.5
CentOS Linux release 7.6.1810
# grep docsroot /usr/local/directadmin/conf/directadmin.conf
demodocsroot=./data/skins/evolution
docsroot=./data/skins/evolution
# grep -r skin /usr/local/directadmin/data/users/*/user.conf
/usr/local/directadmin/data/users/admin/user.conf:docsroot=./data/skins/evolution
/usr/local/directadmin/data/users/admin/user.conf:skin=evolution
/usr/local/directadmin/data/users/myuser1/user.conf:docsroot=./data/skins/evolution
/usr/local/directadmin/data/users/myuser1/user.conf:skin=evolution