Hi,
Replace the current script you are using with the one from here:
Edit the script with the correct settings for user / password etc.
I use Mariadb10 on my Synology and that uses port 3307 instead of 3306, so I use:
Use the Web Station settings on your Synology to set the version to PHP 7.4 (install the package first and make a profile for it within Webstation).