Please report the amount from box O in the “Other boxes on your RL-1” section. To find the relevant box in the “Other boxes on your RL-1” section, type in the code (e.g., "CA"). The amount will be included in box O automatically.
If you have more than one source of income in box O (code RZ), your slip will have boxes like RZ-CA and RZ-OM (for example). Report them the same way as above (e.g., by typing in "CA").