Add a generic logging function to your custom PrestaShop module that will log messages to the Logs page of the Back Office

prestashop_add_to_logs.php

<?php
/**
 * Generic logging function
 *
 * @param $event
 * @param $info
 * @param int $level
 * @param null $supplementary
 * @return bool
 */
public function logGeneric($event, $info, $level = 1, $supplementary = null)
{
    if (!$level) {
        $level = 1;
    };
    
    $customer_id = 'unknown';
    
    if (isset($this->context->customer)) {
        $customer_id = $this->context->customer->id;
    }
    
    $message = sprintf('%s : %s (customer_id : %s%s)',$event, $info, $customer_id,
        ($supplementary) ? sprintf(', supplementary : %s', $supplementary) : '');
    
    return PrestaShopLogger::addLog($message, $level);
}