Failed to load extension to Edge

[ramisedhom]

Microsoft Edge Version: 129.0.2792.79 (Official build) (64-bit)
Obsidian-clipper version: 1.0.0-beta.6

Steps:

1. Unzip the obsidian-clipper-extention.zip file.
2. Open Edge browser and navigate to the Extensions.
3. Enable Developer mode.
4. Click on Load unpacked button and navigate to the unzipped obsidian-clipper-extention directory and select it.

Error:
ErrorMissing 'manifest_version' key. Its value must be an integer either 2 or 3. See developer.chrome.com/extensions/manifestVersion for details.

[ramisedhom]

I added:

{
  ...,
  "manifest_version": 2,
  ...
}

and extension added but the Clipper button is dimmed.