Application installation fails with:
CONFIG_TEXT: The 'mysql' extension was not found
Plesk installed on Ubuntu 16
Plesk > Domains > example.com > PHP Settings shown that the domain is configured with PHP version 7.0.22 by OS vendor
PHP version shipped with Ubuntu 16 does not have mysql module enabled.
Switch PHP version from "by OS vendor" to shipped by Plesk in Plesk > Domains > example.com > PHP Settings