Failed to exec 'docker' exec: "docker": executable file not found in $PATH

Hello Pritunl team,
I have successfully installed Pritunl zero with bastion and proxy working fine on a test Amazon EC2 server.
We ran into “Failed to exec ‘docker’ exec: “docker”: executable file not found in $PATH” and I’ve searched the forum and the solution suggested was to have most updated version of Docker, which I already did.
I overcame the problem by using Amazon Linux 2 and install pritunl zero directly into the ECS instead of running in container.

Now I’ve been tasked to provision another Pritunl server, using Ubuntu 22.04 and running Pritunl in containers.
It’s already working, except the same problem “Failed to exec ‘docker’ exec: “docker”: executable file not found in $PATH”
Server is already running latest version of Docker. Could your team provide support on this? We are looking forward to implement Pritunl in production and thus acquiring license if things work accordingly.

Thank you

This is the error:

My apologies. I just realized that my setup needs to change.
I can run the management, user, and proxy nodes in Docker container.
But Bastion nodes should be installed directly onto the OS.