title: sudo apt update NO_PUBKEY error on raspberry pi 4
body: <p>Im running Raspbian GNU/Linux 10 (buster) on a Raspberry Pi 4 and trying a project, <a href="https://pimylifeup.com/raspberry-pi-internet-speed-monitor/" rel="nofollow noreferrer">https://pimylifeup.com/raspberry-pi-internet-speed-monitor/</a> , where it runs a speedtest and logs the result. I just finished the "Writing our Speed Test Python Script" section and i am trying to update with sudo apt update, but i get this error. <a href="https://i.stack.imgur.com/dmZgu.png" rel="nofollow noreferrer">picture of apt update error</a></p>
  
  <p>I'm super new to linux, and have no idea why it would be updating from ookla.com. The only reason i can think of why its updating from ookla is that i installed <code>sudo pip3 install speedtest-cli</code>, but im really not sure. When i go to the repository it says it's pulling from, <a href="https://ookla.bintray.com/debian%20buster%20Release" rel="nofollow noreferrer">https://ookla.bintray.com/debian buster Release</a> it says Repository path missing or not specified.</p>