You need to fix jenkins setup script

[OdedViner]

https://github.com/devopshydclub/vprofile-project/blob/ci-jenkins/userdata/jenkins-setup.sh

https://www.jenkins.io/blog/2023/03/27/repository-signing-keys-changing/

Debian/Ubuntu LTS release
$ curl -fsSL https://pkg.jenkins.io/debian-stable/jenkins.io-2023.key | sudo tee \
  /usr/share/keyrings/jenkins-keyring.asc > /dev/null
$ echo deb [signed-by=/usr/share/keyrings/jenkins-keyring.asc] \
  https://pkg.jenkins.io/debian-stable binary/ | sudo tee \
  /etc/apt/sources.list.d/jenkins.list > /dev/null

Without fix:

root@ip-ABC:~# sh jenkins-setup.sh 
Hit:1 http://us-east-1.ec2.archive.ubuntu.com/ubuntu focal InRelease
Hit:2 http://us-east-1.ec2.archive.ubuntu.com/ubuntu focal-updates InRelease                          
Hit:3 http://us-east-1.ec2.archive.ubuntu.com/ubuntu focal-backports InRelease                        
Ign:4 https://pkg.jenkins.io/debian-stable binary/ InRelease                                          
Get:5 https://pkg.jenkins.io/debian-stable binary/ Release [2044 B]          
Get:6 https://pkg.jenkins.io/debian-stable binary/ Release.gpg [833 B]           
Hit:7 http://security.ubuntu.com/ubuntu focal-security InRelease                    
Ign:6 https://pkg.jenkins.io/debian-stable binary/ Release.gpg
Reading package lists... Done
W: GPG error: https://pkg.jenkins.io/debian-stable binary/ Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 5BA31D57EF5975CA
E: The repository 'https://pkg.jenkins.io/debian-stable binary/ Release' 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.