public static function send_data( $force = false ) {

		// Don't trigger during AJAX Requests.
		if ( defined( 'DOING_AJAX' ) && DOING_AJAX ) {
			return;
		}

		// Allow forcing of the send despite the interval.
		if ( ! $force && ! apply_filters( 'llms_tracker_force_send', false ) ) {

			// Only send data once a week.
			$last_send = self::get_last_send_time();
			if ( $last_send && $last_send > apply_filters( 'llms_tracker_send_interval', strtotime( '-1 week' ) ) ) {
				return;
			}
		}

		// Record a last send time.
		update_option( 'llms_tracker_last_send_time', time() );

		$r = wp_remote_post(
			self::API_URL,
			array(
				'body'        => array(
					'data' => json_encode( LLMS_Data::get_data( 'tracker' ) ),
				),
				'cookies'     => array(),
				'headers'     => array(
					'user-agent' => 'LifterLMS_Tracker/' . md5( esc_url( home_url( '/' ) ) ) . ';',
				),
				'method'      => 'POST',
				'redirection' => 5,
				'timeout'     => 60,
			)
		);

		if ( ! is_wp_error( $r ) ) {

			return json_decode( $r['body'], true );

		} else {

			return $r;

		}

	}