If your FTP Account is not in use or you want to suspend your account, you can do it from your DirectAdmin account.
Log in to your DirectAdmin Account.
In the Account Manager section, click on the FTP Management Icon or type FTP Management in the navigation filter box. The option will appear. Click on it.
Under Account, choose the account you wish to suspend.
Your FTP Account will be suspended, and later you can start it again by clicking on Unsuspend.