1. PHP REQUIREMENT LINK : https://www.clicshopping.org/forum/technical-information/ and also check /install/templates/pages/ (line 53 i.e if (version_compare(phpversion(), '8.3', '<'))) and https://github.com/ClicShopping#Requirement
2. Timezone : Select New York.
3. Install without demo data.
4. Keep SMTP details blank.
5. 'api_key' column value is hardcoded in `[[dbprefix]]api` table in install/clicshopping.sql, no need to configure.