Plugin doesnt show up

please keep ur promise and give a good support:

http://reisecodes.de/payback/

The plugin doesnt show up in frontend with shortcode like said under installation please help me or give me my money back I bought the pro version. The mistake occured after I gave in my serial, this honestly is crap with the plugin

Regards

https://ww.wp.xz.cn/plugins/smart-forms/