Place your mouse on the right-hand side corner of your screen, over your name and you will see a dropdown list containing your authorized businesses. Then, select "Create a business".
This step will take you to the Business Creation Form. Fill the form and make sure that you are legally authorized to act on the name of that business, as you will need to provide documentation to support that claim.
Once your form has been correctly filled, submit your business' information for review, but your business record will be created successfully and your Alliance ID Tenant will be added as the primary contact for that business.