The repository does not have a Release file

[NTohan]

Adding follow repo to /etc/apt/sources.list

deb http://localhost:49161/debian unstable main contrib non-free

leads to apt update error

E: The repository 'http://localhost:49161/debian unstable 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.