Troubleshooting your Pixelfed installation
Horizon is not working
This means that your permissions are wrong somewhere. Make sure that you have run
php artisan horizon as a user that has access to both your repo and to Redis.
Horizon seems to be working, but it's still showing as inactive.
php artisan package:discover or
composer install, then run
php artisan horizon:install and
php artisan horizon:assets then
php artisan route:cache. Restart your systemd service or restart Horizon. It should now show as active.