Upgrade Business account to PRO

  1. Connect to the PayPal Developer Website
  2. Click on Applications on the horizontal bar
  3. And then on Sandbox Accounts on the left menu
  4. Click on the arrow next your Sandbox business account email address,
    sandbox-arrow
  5. and then click on the Profile link that appears below the email address. 
    sandbox-profileThis opens the Sandbox account details window.
  6. In the window Account details, from the Profile tab of this window, select Upgrade to Pro. Then click the Enable button.
    upgrade-pro-enable
  7. Click on Close. Your Sandbox Business Account has been upgraded
    business-pro