Link a contact to an organization
Go to the Contacts tab and search for your contact (see Searching for a contact). Once you have found your contact, tick the box to the left of their last name to select them.
Once you have selected your contact, go to "More options" and click on "Link to an organization".
A window will then open. Click on the box to display all your previously created organizations, then select the desired one. Finally, click on Save to link your contact to the organization.
Note that a contact can only be linked to one structure.