Man pages matching name cgi::formbuilder::template::cgi_ssi in section 3pm:

CGI::FormBuilder::Template::CGI_SSI.3pm.en	debian 10 / libcgi-formbuilder-perl
CGI::FormBuilder::Template::CGI_SSI.3pm.en	debian 11 / libcgi-formbuilder-perl
CGI::FormBuilder::Template::CGI_SSI.3pm.en	debian 12 / libcgi-formbuilder-perl