toybrick@debian10:~$ sudo apt update
Hit:2 http://mirrors.ustc.edu.cn/debian buster InRelease
Err:1 https://repo.rock-chips.com/toybrick/buster/armhf buster InRelease
401 Unauthorized [IP: 120.27.214.227 443]
Reading package lists... Done
E: Failed to fetch http://repo.rock-chips.com/toybr ... ts/buster/InRelease 401 Unauthorized [IP: 120.27.214.227 443]
E: The repository 'http://repo.rock-chips.com/toybrick/buster/armhf buster InRelease' is no longer 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.