As of April 2021, there is no way to convert a reseller account to a user account from the DA GUI. You must use instead shell commands.
How to convert a reseller account to a user account:
1. Log into DA server with SSH
2. Edit the file
/usr/local/directadmin/data/users/USERNAME/user.conf
and change the username type from
usertype=reseller
to
usertype=user
3. Remove the reseller USERNAME from
/usr/local/directadmin/data/admin/reseller.list
Just edit the file, find the line containing the USERNAME, and remove it.
4. Add the USERNAME to the admin user. Edit the file
/usr/local/directadmin/data/users/admin/users.list
and add on a new row the with the USERNAME.
The USERNAME is now no longer a reseller.
NOTE: the USERNAME is the account name – like “plothost” for example.
Related articles:
How to convert a user to a reseller in DirectAdmin