Yes, you can convert a position from intraday to delivery. 

To do so, go to the trades tab in the bottom panel. By default, you will land onto the Holdings screen, navigate to the positions tab using the top navigation pane.

Here, you can find all the positions that you have taken. To find a specific position you are looking for, you can search or cut through the clutter using sort and filter.

Once you find the entry you are looking for, simply tap on the positions on the list to view more details from here you can choose to convert it from intraday to delivery or viceversa.