I am gladly using codeberg (as github alternative) for as many projects as I can, really support their mission. "Independent and powered by your donations and contributions".
I struggled a little bit to figure out the URL that works for a package that is not on npm yet, but exists just as a codeberg repo.

Npm Module From a Repo

Npm modules are normally installed via npm install <package-name>, but this works only once the package is published on npm. If I try to install npm install test-stitcher, this fails.

To work with a package straight from the repository one can also use a URL as dependency, for a codeberg repo it works like this: npm install git+https://codeberg.org/wolframkriesing/test-stitcher.git. The URL is used as the package name, just the prefix "git+https" was what I had to try and play with until I figured it out.

Failed Tries

I tried a lot of the known URL patterns as dependency in my package.json.
Those that failed were:

* https://codeberg.org/wolframkriesing/test-stitcher.git
* git://codeberg.org/wolframkriesing/test-stitcher.git
* git@codeberg.org:wolframkriesing/test-stitcher.git
* git+ssh://git@codeberg.org/wolframkriesing/test-stitcher.git
* git+ssh://git@codeberg.org:wolframkriesing/test-stitcher.git
* git+https://codeberg.org/wolframkriesing/test-stitcher.git 

Just to quote one error that I received when I called npm install:

> npm install
npm ERR! code ENOLOCAL
npm ERR! Could not install from "git@codeberg.org:wolframkriesing/test-stitcher.git" as it does not contain a package.json file.

How it Works

The URL that works is prefixed with "git+https":

git+https://codeberg.org/wolframkriesing/test-stitcher.git

{
  "dependencies": {
    "test-stitcher": "git+https://codeberg.org/wolframkriesing/test-stitcher.git"
  }
}

I have not seen and used the combination "git" and "https" before, but hey if npm accepts this. Cool. hth