Source

File: wp-includes/rest-api/endpoints/class-wp-rest-plugins-controller.php

protected function get_plugin_status( $plugin ) {
		if ( is_plugin_active_for_network( $plugin ) ) {
			return 'network-active';
		}

		if ( is_plugin_active( $plugin ) ) {
			return 'active';
		}

		return 'inactive';
	}