Update Problem -public key is not available

[Ssoc]

root@sip:/home/ags# apt update && apt upgrade -y
Get:1 http://security.debian.org buster/updates InRelease [65.4 kB]
Get:2 http://ftp.debian.org/debian buster InRelease [122 kB]
Get:3 http://security.debian.org buster/updates/main amd64 Packages [267 kB]
Get:4 http://apt.postgresql.org/pub/repos/apt buster-pgdg InRelease [104 kB]
Get:5 http://ftp.debian.org/debian buster-updates InRelease [51.9 kB]
Get:6 http://security.debian.org buster/updates/main Translation-en [142 kB]
Get:7 http://ftp.debian.org/debian buster/main amd64 Packages [7907 kB]
Err:4 http://apt.postgresql.org/pub/repos/apt buster-pgdg InRelease
The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7FCC7D46ACCC4CF8
Get:8 http://files.freeswitch.org/repo/deb/debian-release buster InRelease [3936 B]
Get:9 http://files.freeswitch.org/repo/deb/debian-release buster/main amd64 Packages [64.9 kB]
Get:10 http://ftp.debian.org/debian buster/main Translation-en [5969 kB]
Get:11 http://ftp.debian.org/debian buster/contrib amd64 Packages [50.1 kB]
Get:12 http://ftp.debian.org/debian buster/contrib Translation-en [44.2 kB]
Get:13 http://ftp.debian.org/debian buster-updates/main amd64 Packages.diff/Index [5656 B]
Get:14 http://ftp.debian.org/debian buster-updates/main Translation-en.diff/Index [3688 B]
Get:15 http://ftp.debian.org/debian buster-updates/main amd64 Packages 2020-12-24-1401.30.pdiff [286 B]
Get:16 http://ftp.debian.org/debian buster-updates/main amd64 Packages 2021-01-29-2000.47.pdiff [408 B]
Get:17 http://ftp.debian.org/debian buster-updates/main amd64 Packages 2021-02-07-1359.56.pdiff [2302 B]
Get:17 http://ftp.debian.org/debian buster-updates/main amd64 Packages 2021-02-07-1359.56.pdiff [2302 B]
Get:18 http://ftp.debian.org/debian buster-updates/main Translation-en 2021-02-07-1359.56.pdiff [1506 B]
Get:18 http://ftp.debian.org/debian buster-updates/main Translation-en 2021-02-07-1359.56.pdiff [1506 B]
Reading package lists... Done
N: Repository 'http://ftp.debian.org/debian buster InRelease' changed its 'Version' value from '10.7' to '10.8'
W: GPG error: http://apt.postgresql.org/pub/repos/apt buster-pgdg InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7FCC7D46ACCC4CF8
E: The repository 'http://apt.postgresql.org/pub/repos/apt buster-pgdg 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.
root@sip:/home/ags#

How may I fix it?

thanks in advance,
tony

 

[Ssoc]

Thanks
I did it.

 

[Adrian Fretwell]

Thanks
I did it.

I'm glad you managed to sort it yourself, please post what you did, it will help others.