Install instruction doesn't work, return gpg: keyserver receive failed: Network is unreachable

gpg export commands fail even with the 3 alternative URLs.
<img width="765" alt="image" src="https://user-images.githubusercontent.com/41361698/212322551-86e221e8-ba2a-4d1c-b0e0-b7e84508a49a.png">
The response is here:
<img width="1481" alt="image" src="https://user-images.githubusercontent.com/41361698/212323053-ce3cc37b-f0f7-409e-a240-6aeb61f170e1.png">
