title: Unable to install Jenkins on Ubuntu 20.04
body: <p>I am trying to install Jenkins on my Ubuntu EC2 instance and I performed the following steps to install but couldn't install it.</p>
  <p>$sudo apt update
  $sudo apt install openjdk-8-jdk
  $wget -q -O - <a href="https://pkg.jenkins.io/debian-stable/jenkins.io.key" rel="noreferrer">https://pkg.jenkins.io/debian-stable/jenkins.io.key</a> | sudo apt-key add -
  $sudo sh -c 'echo deb <a href="http://pkg.jenkins.io/debian-stable" rel="noreferrer">http://pkg.jenkins.io/debian-stable</a> binary/ &gt; /etc/apt/sources.list.d/jenkins.list'
  $sudo apt update   &lt;--------- (Here I am getting below error)</p>
  <p><strong>root@ip-172-31-44-187:~# sudo apt update
  Ign:1 <a href="https://pkg.jenkins.io/debian-stable" rel="noreferrer">https://pkg.jenkins.io/debian-stable</a> binary/ InRelease
  Err:2 <a href="https://pkg.jenkins.io/debian-stable" rel="noreferrer">https://pkg.jenkins.io/debian-stable</a> binary/ Release
  Certificate verification failed: The certificate is NOT trusted. The certificate chain uses expired certificate.  Could not handshake: Error in
  the certificate verification. [IP: 151.101.154.133 443]
  Hit:3 <a href="http://ap-south-1.ec2.archive.ubuntu.com/ubuntu" rel="noreferrer">http://ap-south-1.ec2.archive.ubuntu.com/ubuntu</a> focal InRelease
  Get:4 <a href="http://ap-south-1.ec2.archive.ubuntu.com/ubuntu" rel="noreferrer">http://ap-south-1.ec2.archive.ubuntu.com/ubuntu</a> focal-updates InRelease [114 kB]
  Get:5 <a href="http://security.ubuntu.com/ubuntu" rel="noreferrer">http://security.ubuntu.com/ubuntu</a> focal-security InRelease [114 kB]
  Get:6 <a href="http://ap-south-1.ec2.archive.ubuntu.com/ubuntu" rel="noreferrer">http://ap-south-1.ec2.archive.ubuntu.com/ubuntu</a> focal-backports InRelease [101 kB]
  Reading package lists... Done
  E: The repository 'http://pkg.jenkins.io/debian-stable binary/ 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.</strong></p>