Touch the Settings icons at the lower right:
Touch the Title Page icon and the Title Page will be displayed:
Touch the screen to display the keyboard and you can add what you need.
Press the Down arrow at the upper left when you're finished and want to return to the script pages.
NOTE that title page functionality is limited in the Mobile App; if you need to insert tab-stopped text, you can do so in Final Draft 10 / 9 / 8.