Answers for "fatal error: composer detected issues in your platform: your composer dependencies require a php version ">= 7.2.5". you are running 7.1.33-3+ubuntu16.04.1+deb.sury.org+1. in /var/dev/affiliz/vendor/composer/platform_check.php on line 24"

Composer detected issues in your platform: Your Composer dependencies require a PHP version ">= 7.3.0".

composer install --ignore-platform-reqs

Composer detected issues in your platform: Your Composer dependencies require a PHP version ">= 7.3.0".

composer install --ignore-platform-reqs

or 
 #add to composer.json > config
"platform-check": false,

composer autoload-dump