You can specify a number of Buttons which will be rendered at the bottom of the form.
Each button has a type and a role.
Currently supported types are:
text_buttonoutline_buttonraised_button
These are styled according to the corresponding Material Design specifications.
Supported roles are:
submit, which submits the form according to theform'ssubmit_topropertyback, which navigates the app up one level if possible
{
"type": "text_button",
"role": "submit",
"text": "Save"
}