Plugin Error:create 2 custom field error

Hai., I have installed the following plugin in my shopware4.3.3. https://gist.github.com/sthamann/5343247 When i tried to finish checkout,The following error occured in the below link http://www.********.de/checkout/finish Here is the Error: [color=red]Fatal error: Call to undefined method Shopware\Models\Attribute\Order::setOrdermodRandom1() in /home/raptis-family/www/htdocs/engine/Shopware/Plugins/Local/Frontend/OrderMod/Bootstrap.php on line 62 503 Service Unavailable[/color] Please help me to find a solution Thankyou

I’ve created installation ZIP for this plugin. Please make sure that your directory structure is correct. You can find it here. Another thing: check database if new columns are added to s_order_attributes table (ordermod_Random1, ordermod_Random2). If they’re missing, reinstall plugin and make sure it installs without any errors. You can also try to clear (proxies and metadata) cache.