Be sure to activate the section via the 4 squares via Top right of the form.
20 E Add Gross Assessable Foreign Source Income here. i.e. before related expenses.
T - O Add the Net Foreign Income by type. i.e. after related expenses.
Note - 20 U Net Foreign Employment Income - Payment Summary. Use this ONLY if you've already completed a payment summary. Mostly this will apply to people earning wages from an Australian entity but posted overseas.