Setting up youtube-dl while running tgs in a docker container.

[Useroth]

Due to how docker works, having its own isolated environment, some things are troublesome to set up.
Basically, the process consists of two steps.

First, you need to run a shell inside the container, let's take bash for the example, you can substitute it for whatever you want.
docker exec -it YOUR_TGS_CONTAINER_NAME /bin/bash

Then, from there install youtube-dl through your distro's package manager, or alternatively another method, if you prefer it so, since it ultimately is just a python script.

Should you choose to do the package manager path, some distros, such as debian, have very outdated "stable" repositories, which will deliver an outdated and non-functional version of it, so you might need to adjust to enable "testing" or "unsable" repos to get one that will work.