Install has errors (see attached) Please help


I am trying to install on Ubuntu 18.04.2 x 64 hosted on Digital ocean.

Following this install guide from Git

I am getting an error about signatures and public key is not listed
See this error below from screen shot.

what can I do to fix this



Did you execute this: wget -qO - | apt-key add -?


yes and I got no errors. But I just got it working or at least installed. I watched the video and did all the commands as he did in video and it was completed with out errors. These are a few steps in video that are not in this quick start so it others are having the same issue just follow all the steps in the video as this worked for me. Thank you for your super fast reply.