Detect an reactivate an inactive plugin

// Scheduler
add_action( 'admin_notices', function() {

	// Require Action Scheduler
	if( ! function_exists( 'as_has_scheduled_action' ) ) {
		printf(
			'
				<div class="notice notice-warning is-dismissible">
					<p>%s</p>
				</div>
			', 'Plugin reactivator -- Missing Action Scheduler.'
		);
		return;
	}

	// Check Preexistence
	$hook = 'ccom_plugin_reactivator';
	if( ! as_has_scheduled_action( $hook ) ) {

		// Set New Schedule
		as_schedule_recurring_action(
			current_time( 'timestamp', 1 ),
			15 * MINUTE_IN_SECONDS,
			$hook
		);

	}

} );

// Runner
add_action( 'ccom_plugin_reactivator', function() {

	// Setting
	$plugin_file = 'klaviyo/klaviyo.php';

	// Check Plugin Status
	if( is_plugin_active( $plugin_file ) ) {
		return;
	}

	// Activate It
	activate_plugin( $plugin_file, '', false, true );

} );