This script allows you to park multiple domains to multiple accounts with a CSV file, please note that it has everything I need for my accounts and to add/remove please refer to the API documentation (https://documentation.cpanel.net/display/SDK/cPanel+API+2+Functions+-+Park%3A%3Apark)
Please Note: You require to have the ability to login to user's account with your root password (https://documentation.cpanel.net/display/ALD/Log+in+to+a+User's+Account+with+the+Root+Password)