What are the minimum requirements for Maps Marker Pro?

In order to be able to install Maps Marker Pro, the following minimum requirements have to be fulfilled:

PHP 5.4 or higher (a current 7.x version is recommended, PHP compatibility has been tested with 7.0, 7.1, 7.2 and 7.3)
WordPress 4.5 or higher or ClassicPress.
For verifying the license key, your server needs to be able to connect to www.mapsmarker.com via port 443

403