cd into the application folder and run composer install --no-dev.
Copy the .env.example file to .env and fill with your own database and mail details.
Ensure the storage, bootstrap/cache & public/uploads folders are writable by the web server.
In the application root, Run php artisan key:generate to generate a unique application key.
If not using Apache or if .htaccess files are disabled you will have to create some URL rewrite rules as shown below.
Set the web root on your server to point to the BookStack public folder. This is done with the root setting on Nginx or the DocumentRoot setting on Apache.
Run php artisan migrate to update the database.
Done! You can now login using the default admin details admin@admin.com with a password of password. You should change these details immediately after logging in for the first time.