The last option in your dropdown is what you are looking for (Vacation_Submitter) and you can assign an account to that.
Edit: I see now where you’ve gone wrong. You've created submitter and approver entities. You submitter and approver associations should be connected to the account entity instead.
Go to your domain model, double click the entity, go to the associations tab, remove the current associations, and then add them as associations to Account.
Hope this helps
Thank for feedback
What I look for is Administration Entity because within “Create New object” window, I would like to create a “ New member” throughout “Edit change item” . And there, I can’t add “Administrator.Account “ as member type like in the first screeshot.