The expected 'Store URL' for this app is your storefront URL in the following example formats:
'Store URL' is the same website address that your end-customers use to access your storefront.
Common incorrect formats are:
Please note that 'Admin URL' is not the valid format of 'Site URL' for this app.
If your input 'Store URL' is in the required format and you are still constantly getting a Store URL invalid error, it is likely that your Apache configuration is not set to allow PrestaShop .htaccess to work.
To fix this issue, please do the following:
Locate your Apache configuration file. It is usually at located at one of the following locations on your server:
Enable rewrites, by adding option 'AllowOverride All' as in the following:
Options Indexes FollowSymLinks
Require all granted
'yourPrestaShopDirectory' path must match the location of your Magento installation on your server file system. After changing the configuration, restart the Apache server.