• To Login, you need:
  

• API Path
  
• Client ID
  
• Access Token
  

• To get credentials, Login to your BigCommerce Admin Panel. Go to Advanced Settings.
  

• Click on 'API Accounts' & 'Create API Account'
  

• Enter a desired name (e.g.: aquaAPI POS), and  provide OAuth scopes suggested on next screen
  

• Copy API Path. Save.
  
• Copy Client ID & Access Token from next screen.
  

• API Path, Client ID & Access Token are all you need to login.