To add a member manually from the admin, go to Members >> Search Members and simply use the "Add New Member" button in the admin:

This will open a pop up window which will prompt you to enter the Account status, Membership Plan, Email and Password as required information:

You will also be able to add the member's account details just like in the Contact Details section of the member dashboard:

Once you enter the information, can click on the "Create New Account" button. Once created, the option to log in as the member will display and you will be able to complete the rest of the member's profile information: