Activate SearchWP using code. Also available as a plugin for WordPress Multisite: https://github.com/soderlind/ms-searchwp-subsite-activate

activate-searchwp.php

<?php
// Define the license key e.g. in wp-config.php
define( 'SEARCHWP_LICENSE_KEY', 'my-license-key-goes-here' );



// Programmatically activate the license and enable SearchWP. 
add_action( 'admin_init', 'searchwp_activate' );
function searchwp_activate() {
	if ( defined( 'SEARCHWP_LICENSE_KEY' ) && class_exists( '\SearchWP_License' ) && false === get_option( 'soderlind_searchwp_license_activated', false ) ) {
		$swp_license = new \SearchWP_License();
		$swp_license->activate( SEARCHWP_LICENSE_KEY );
		searchwp_set_setting( 'initial_settings', true ); // tell SearchWP to work with the default generated config on install.
		\SWP()->trigger_index(); // Run the SearchWP indexer
		update_option( 'soderlind_searchwp_license_activated', true );
	}
}