Interestingly, I just installed perl-doc on my Ubuntu system a few weeks ago, and the process was rather straightforward, as seen copied from the terminal:

---

# perldoc Test::More
You need to install the perl-doc package to use this program.
# apt install perl-doc
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following NEW packages will be installed:
  perl-doc
0 upgraded, 1 newly installed, 0 to remove and 91 not upgraded.
Need to get 7,819 kB of archives.
After this operation, 15.2 MB of additional disk space will be used.
Get:1 http://th.archive.ubuntu.com/ubuntu jammy-updates/main amd64 per
+l-doc all 5.34.0-3ubuntu1.2 [7,819 kB]
Fetched 7,819 kB in 1s (6,704 kB/s)    
Selecting previously unselected package perl-doc.
(Reading database ... 414805 files and directories currently installed
+.)
Preparing to unpack .../perl-doc_5.34.0-3ubuntu1.2_all.deb ...
Adding 'diversion of /usr/bin/perldoc to /usr/bin/perldoc.stub by perl
+-doc'
Unpacking perl-doc (5.34.0-3ubuntu1.2) ...
Setting up perl-doc (5.34.0-3ubuntu1.2) ...
Processing triggers for man-db (2.10.2-1) ...
Scanning processes...                                                 
+                                                                     
+                                      
Scanning candidates...                                                
+                                                                     
+                                      
Scanning linux images...                                              
+                                                                     
+                                      

Restarting services...
 /etc/needrestart/restart.d/systemd-manager
 systemctl restart packagekit.service ssh.service systemd-journald.ser
+vice systemd-networkd.service systemd-resolved.service systemd-timesy
+ncd.service systemd-udevd.service udisks2.service upower.service
Service restarts being deferred:
 /etc/needrestart/restart.d/dbus.service
 systemctl restart getty@tty1.service
 systemctl restart networkd-dispatcher.service
 systemctl restart systemd-logind.service
 systemctl restart unattended-upgrades.service
 systemctl restart user@1000.service

No containers need to be restarted.

No user sessions are running outdated binaries.

No VM guests are running outdated hypervisor (qemu) binaries on this h
+ost.
[download]

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I would wonder, if you cannot find the perl-doc package, if perhaps your repositories are incorrectly setup and/or your network connection has some issues. What exactly did the error message say?

You might also check if issuing a command like:

# apt-cache search perl-doc
[download]

...nets anything useful. It should show up in the list, e.g.:

# apt-cache search perl-doc
perl-base - minimal Perl system
perl-doc - Perl documentation
libgdal-perl-doc - Documentation for the GDAL Perl bindings
libhtml-mason-perl-doc - HTML::Mason examples
libsbml5-perl-doc - System Biology Markup Language library -- Perl doc
+umentation
perl-doc-html - Perl documentation suitable for viewing with a web bro
+wser
w3m-el - simple Emacs interface of w3m
w3m-el-snapshot - simple Emacs interface of w3m (development version)
[download]