Stuck with 500 error after weird bugs and a rebuild

HI,
I also admin the same server and here’s what I’ve done so far.
I have upgraded the host from focal to jammy, removed all the images and re-downloaded new ones.
I discovered we were on the master branch so I changed to main branch.
made sure I was on latest commit.

It now builds but we still have an error 500 issue.
I looked at the unicorn logs and found it spamming:

E, [2024-01-07T04:58:49.140147 #682] ERROR -- : app error: Missing `secret_key_base` for 'production' environment, set this string with `bin/rails credentials:edit` (ArgumentError)
E, [2024-01-07T04:58:49.140266 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/railties-7.0.8/lib/rails/application.rb:576:in `validate_secret_key_base'
E, [2024-01-07T04:58:49.140278 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/railties-7.0.8/lib/rails/application.rb:419:in `secret_key_base'
E, [2024-01-07T04:58:49.140287 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/railties-7.0.8/lib/rails/application.rb:254:in `env_config'
E, [2024-01-07T04:58:49.140295 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/railties-7.0.8/lib/rails/engine.rb:716:in `build_request'
E, [2024-01-07T04:58:49.140304 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/railties-7.0.8/lib/rails/application.rb:598:in `build_request'
E, [2024-01-07T04:58:49.140311 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/railties-7.0.8/lib/rails/engine.rb:529:in `call'
E, [2024-01-07T04:58:49.140319 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/railties-7.0.8/lib/rails/railtie.rb:226:in `public_send'
E, [2024-01-07T04:58:49.140327 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/railties-7.0.8/lib/rails/railtie.rb:226:in `method_missing'
E, [2024-01-07T04:58:49.140336 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/rack-2.2.8/lib/rack/urlmap.rb:74:in `block in call'
E, [2024-01-07T04:58:49.140344 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/rack-2.2.8/lib/rack/urlmap.rb:58:in `each'
E, [2024-01-07T04:58:49.140353 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/rack-2.2.8/lib/rack/urlmap.rb:58:in `call'
E, [2024-01-07T04:58:49.140368 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:634:in `process_client'
E, [2024-01-07T04:58:49.140378 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:739:in `worker_loop'
E, [2024-01-07T04:58:49.140386 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:547:in `spawn_missing_workers'
E, [2024-01-07T04:58:49.140409 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/unicorn-6.1.0/lib/unicorn/http_server.rb:143:in `start'
E, [2024-01-07T04:58:49.140417 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/gems/unicorn-6.1.0/bin/unicorn:128:in `<top (required)>'
E, [2024-01-07T04:58:49.140426 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/bin/unicorn:25:in `load'
E, [2024-01-07T04:58:49.140434 #682] ERROR -- : /var/www/discourse/vendor/bundle/ruby/3.2.0/bin/unicorn:25:in `<main>'

This is currently my only indication of what is wrong.