Actions -> removeField
Remove a specific field by id or leave blank to remove the last field.
Usage
var fbEditor = document.getElementById('build-wrap');
var options = {
formData: JSON.stringify([{
type: 'text'
}])
};
var formBuilder = $(fbEditor).formBuilder(options);
document.getElementById('remove-field').addEventListener('click', function() {
formBuilder.actions.removeField();
});