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.

Note that, only these values ( T, L, D, R, F, M1, and M2) from "Income > Foreign" step are calculating to "Total Income > Estimate"

In this example, $3000 is the total amount of T+L+D+M1+M2. 

Related Article:

NRFI Schedule