To view Perl CGI errors in a web browser, you will need to have error reporting enabled in your Perl CGI scripts. This is typically done by adding the following line at the top of your Perl CGI script:
use CGI::Carp qw(fatalsToBrowser);
This will cause any fatal errors that occur during the execution of your Perl CGI script to be displayed in the web browser, along with a detailed error message.
If you are not seeing any error messages in the web browser, it is possible that error reporting has been disabled in your Perl CGI scripts. In this case, you can try enabling it by adding the line of code above to your scripts.
Alternatively, you can check the web server error logs to see if there are any errors being recorded there. On most systems, the web server error logs are located in a directory like /var/log/httpd or /var/log/apache2. You can view the error logs by using a command like tail -f /var/log/httpd/error_log or tail -f /var/log/apache2/error.log.