sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 6494C6D6997C215E
Utils: https://www.digitalocean.com/community/tutorials/how-to-install-jenkins-on-ubuntu-18-04 https://pkg.jenkins.io/debian-stable/ Solve the problem by adding this: wget -q -O - https://pkg.jenkins.io/debian-stable/jenkins.io.key | sudo apt-key add -