Information processing apparatus capable of extending print functions and storage medium

An information processing apparatus comprising:

• one or more memories that store print data generation software, an extension application program for supporting the print data generation software usable for a plurality of printing apparatuses of vendors, print function information, and an operating system performing control so that medium information newly added to the print function information is displayed preferentially;
• and
• a processor that causes, by executing the extension application program, the information processing apparatus to
• acquire medium information from a printing apparatus;
• add the acquired medium information to the print function information so that the medium information existing in the print function information is displayed prior to the acquired medium information;
• and
• cause the information processing apparatus to display, based on the print function information, a medium selecting screen so that the medium information existing in the print function information is displayed prior to the added medium information.