Composer error when try install extension

I’m getting this when i’m trying to install an extension.

Warning: Unsupported declare ‘strict_types’ in
/home/SITE_NAME/public_html/vendor/magento/inventory-composer-installer/src/Plugin.php
on line 6

Parse error: syntax error, unexpected ‘:’, expecting ‘;’ or ‘{‘ in
/home/SITE_NAME/public_html/vendor/magento/inventory-composer-installer/src/Plugin.php
on line 55

I have : CentOS Linux release 7.5.1804 (Core); PHP 7.2 (via cPanel) ; Latest magento 2.3.3 CE

php -v
PHP 5.6.40 (cli) (built: Oct 29 2019 08:07:50)

Need Some Help