Create a simple PHP script (50-80 lines of code)

The project is to create a simple PHP script to receive data from ActiveCampaign's webhook and do some MySQL scripts on a MySQL server. If somebody would subscribe on a form, active campaign would call the script and the script needs to create a new database with the data provided in the POST parameters. Some parameters would be validated through ROT13. On of the input parameters is the IP address of the user, from which the country should be decoded through ip-api.com. Based on the COUNTRY of origin, the database should be created on the ideal MySQL server (closest based on a country list). The country and other input parameters (and some default values) should be inserted into the new DB, and based on an etalon database the default tables should be copied.