Hardwire Ninja Forms from name and from address.

hardwire-njnjaform-from.php

<?php

/**
 * Hardwire Ninja Forms from name and from address.
 */
add_filter( 'ninja_forms_run_action_settings', function ( $action_settings, $form_id, $action_id, $form_settings ) {

	if ( 'email' === $action_settings['type'] ) {
			$action_settings['from_name'] = 'from name';
			$action_settings['from_address'] = 'from@name.tld';
	}

  return $action_settings;
},  10, 4 );