Can't ping from within the container

I am trying to set up LibreNMS docker container, but can’t add any device. When I tried to add my router, I see the following on the web console:
Adding host community public port 161 using udp
Could not ping

From the docker shell, I get response back if I curl, but I can’t ping.

Here’s my response from validate.php
bash-5.0$ ./validate.php
Component Version
LibreNMS 1.70.1
DB Schema 2020_11_02_164331_add_powerstate_enum_to_vminfo (191)
PHP 7.3.25
Python 3.8.5
MySQL 10.4.17-MariaDB-1:10.4.17+maria~focal
RRDTool 1.7.2

[OK] Installed from the official Docker image; no Composer required
[WARN] You have no devices.
Consider adding a device such as localhost: /addhost
[OK] Database connection successful
[OK] Database schema correct
[WARN] IPv6 is disabled on your server, you will not be able to add IPv6 devices.
[WARN] Log rotation not enabled, could cause disk space issues
sudo cp /opt/librenms/misc/librenms.logrotate /etc/logrotate.d/librenms
[WARN] Updates are managed through the official Docker image

Any guidance is appreciated,
Thank you.