Unable to install on Chromebook

Hi. Trying to install on Chromebook, latest chromeos release.

From Linux Terminal I am doing the following:

NOTE - i am following the debian instructions exactly but this forum wont let me post the txt as it thinks i am posting links and new users are limited to two links. All of the apt-get update and adding deb shows URL so i can’t add them in this?

billb@penguin:$ sudo apt-get install lutris
Reading package lists… Done
Building dependency tree
Reading state information… Done
E: Unable to locate package lutris

I have tried restarting multiple times, removing and readding the repo. Browsing the repo directly via chrome shows the .deb file.

Not sure whats going on?

try using the unstable debian release, worked for me