Systems and methods for interfacing with a website to modify content

A non-transitory machine-readable medium having stored thereon machine-readable instructions executable to cause performance of operations comprising:

• after a user access of a checkout webpage, executing a browser extension software installed on a user device with a display, the executing comprising:
• generating a graphical user-selectable element to be presented on the display of the user device and retrieving a selected plurality of digital codes, from a computing device and via a network, to be applied to the checkout webpage;
• storing, by the browser extension software on the user device, the selected plurality of digital codes that cause a change in a certain numerical value on the checkout webpage when applied via the graphical user-selectable element using an operation of the browser extension software;
• and
• after a user selection of the graphical user-selectable element, automatically performing, by the operation, following steps including:
• using at least one of the selected plurality of digital codes to invoke a respective function on the checkout webpage for the at least one of the selected plurality of digital codes without user entry of the at least one of the selected plurality of digital codes, thereby causing the checkout webpage to receive the at least one of the selected plurality of digital codes and to return a respective response to the at least one of the selected plurality of digital codes;
• determining the respective returned response to at least one of the selected plurality of digital codes from the checkout webpage to determine whether the at least one of the selected plurality of digital codes causes the change in the certain numerical value and determine a respective amount of the change in the certain numerical value caused by the at least one of the selected plurality of digital codes;
• and
• after the user selection of the graphical user-selectable element, applying the at least one of the selected plurality of digital codes if the respective amount of change in the certain numerical value caused by the at least one of the selected plurality of digital codes is greater than zero.

A method to operate a user device, comprising:

• receiving, over a network by a plug-in software for an application installed on the user device, a plurality of digital codes;
• storing the plurality of digital codes in association with an operation of the plug-in software that causes a certain numerical value to change when one or more of the plurality of digital codes are applied to a checkout webpage of a third-party retailer website;
• responsive to a user selection of a button to access the checkout webpage, generating a graphical user-selectable element to be presented on a display;
• responsive to a user selection of the graphical user-selectable element, automatically performing following steps:
• using at least one digital code of the plurality of digital codes in the checkout webpage to invoke a respective function on the checkout webpage, without user entry of the at least one digital code, thereby triggering the checkout webpage to receive the at least one digital code and to return a respective response to the at least one digital code,
• determining the respective returned response to the at least one digital code from the checkout webpage to determine whether the at least one digital code causes a change in the certain numerical value and determine a respective amount of change in the certain numerical value caused by at least one digital code, and
• storing in a memory the at least one digital code along with data that shows a respective amount the at least one digital code causes the certain numerical value to change in value;
• and
• after the user selection of the graphical user-selectable element, applying the at least one of the digital codes if the respective amount of change in the certain numerical value caused by the at least one of the digital codes satisfies a criteria.