🐛The repository 'https://pkg.cloudflareclient.com lunar Release' does not have a Release file.

when I try to update the app `sudo apt update`

Then this issue happened.

```
Hit:6 http://archive.ubuntu.com/ubuntu lunar-updates InRelease

Err:7 https://pkg.cloudflareclient.com lunar Release

404 Not Found [IP: 104.19.236.24 443]

Hit:8 http://archive.ubuntu.com/ubuntu lunar-backports InRelease

Hit:9 http://archive.ubuntu.com/ubuntu lunar-security InRelease

Reading package lists... Done

E: The repository 'https://pkg.cloudflareclient.com lunar Release' does not have a Release file.

N: Updating from such a repository can't be done securely, and is therefore disabled by default.

N: See apt-secure(8) manpage for repository creation and user configuration details.
```

**How to fix it?**