(base) jie@jie-MS-7D30:~$ sudo apt update
Hit:1 http://mirrors.aliyun.com/ubuntu focal InRelease
Hit:2 http://mirrors.aliyun.com/ubuntu focal-security InRelease
Hit:3 http://mirrors.aliyun.com/ubuntu focal-updates InRelease
Hit:4 http://mirrors.aliyun.com/ubuntu focal-proposed InRelease
Hit:5 http://mirrors.aliyun.com/ubuntu focal-backports InRelease
Hit:6 https://nvidia.github.io/libnvidia-container/stable/deb/amd64 InRelease
Get:7 https://apt.v2raya.org v2raya InRelease [9,794 B]
Err:7 https://apt.v2raya.org v2raya InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 354E516D494EF95F
Reading package lists... Done
W: GPG error: https://apt.v2raya.org v2raya InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 354E516D494EF95F
E: The repository 'https://apt.v2raya.org v2raya InRelease' is not signed.
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.