To insert text within the image card, first select the pose and click on Edit icon.
Then click on Text tool, erase placeholder text by clicking Delete button on your keyboard, and enter your text in the text window. When you finish, click Enter on your keyboard or click on Select tool. The text will become an object that you can move and resize. Position your text wherever you like. Keep in mind that poses look small when printed, so it is best to make your text larger.
If you want to edit the text that you have already placed, click on Text tool first and then click on your text. Text will become editable. Edit it and then click Enter on your keyboard (or click on Select tool).