To configure your own fields, double tap first on any student in your grade book
You'll be presented with this screen
Tap on the three dots button on the corner to bring the edition options on screen
This will let you add or remove your own personal fields grouped by a section. In our example, we will add two phone numbers (i.e. Phone 1 and Phone 2) and we will name our section Emergency.
And the resulting screen ,with our new fields will look like this