You can override the artist and title text displayed on a QuickCart by editing the cart settings. To do this, first ensure you're in Edit operation mode by clicking the pencil button. Then click on the QuickCart you want to modify to open the Edit QuickCart window.

In the Edit QuickCart window, you'll find Artist and Title checkboxes with text boxes next to them. Tick the Artist checkbox and type your desired artist name into the text box to override the displayed artist. Similarly, tick the Title checkbox and enter your preferred title text to override the displayed title. Once you've made your changes, click OK to confirm and apply them to the QuickCart.