When configuring the Advertising.com Dynamic Retargeter Tag (ADR), you select the page type from the drop-down list. What this action does in the background is set the 'pty' variable (something that the ADR Tag recognizes for page type) to a certain value. So, when you select 'Home Page' from the Page Type drop-down list, you are setting 'pty' to 'hp'. You have the option to override or dynamically set the Page Type by mapping the appropriate data source to pty.
Before you add the ADR Tag, make certain the E-Commerce Extension is set up and configured. The E-Commerce variables this Tag uses are _cprod, _corder, _csubtotal, and _ccat.
Begin by creating a data source to hold the specific page type value you want to send. Next, use the Tag's mapping toolbox to map the data source to pty. Then, add a Lookup table Extension to set the value of the page type data source you created.
Then Save and Publish your changes by clicking the Save/Publish button in the top right corner.