You need to find where the modules were installed so that you can supply those paths to lib pragma: use lib '/path/to/module';. Or, install the software on your own in known locations.

One way to find the file paths of system installed software ...

# Locate LWP::UserAgent.
% rpm -qa | fgrep -i useragent

# Take the name from above to find the installed paths.
% rpm -ql <package name> | fgrep LWP/UserAgent
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Then use the paths from above command output to supply to lib pragma.

Below is an example for "DBD::SQLite" module installed here on CentOS 8 ...

% rpm -qa | egrep -i '(perl|p5).+SQLite'
perl-DBD-SQLite-1.58-2.module_el8.1.0+207+bdacd7b7.x86_64

% rpm -ql perl-DBD-SQLite-1.58-2.module_el8.1.0+207+bdacd7b7.x86_64 | 
+fgrep 'DBD/SQLite'
/usr/lib64/perl5/vendor_perl/DBD/SQLite
/usr/lib64/perl5/vendor_perl/DBD/SQLite.pm
/usr/lib64/perl5/vendor_perl/DBD/SQLite/Constants.pm
/usr/lib64/perl5/vendor_perl/DBD/SQLite/Cookbook.pod
/usr/lib64/perl5/vendor_perl/DBD/SQLite/Fulltext_search.pod
/usr/lib64/perl5/vendor_perl/DBD/SQLite/VirtualTable
/usr/lib64/perl5/vendor_perl/DBD/SQLite/VirtualTable.pm
/usr/lib64/perl5/vendor_perl/DBD/SQLite/VirtualTable/FileContent.pm
/usr/lib64/perl5/vendor_perl/DBD/SQLite/VirtualTable/PerlData.pm
/usr/lib64/perl5/vendor_perl/auto/DBD/SQLite
/usr/lib64/perl5/vendor_perl/auto/DBD/SQLite/SQLite.so


# In Perl program, if "/usr/lib64/perl5/vendor_perl" had not been
# already included in @INC which it is per "perl -V" (near the bottom)
+.
...
use lib q[/usr/lib64/perl5/vendor_perl];
...
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