Refining the violin or developing an analogue

I want to buy such a script
https://php-market.ru/gotovyy-skript-haypa-onlayn-...
Looking for a programmer who could make some changes to the user as well as the admin project.
The script is based on H-script, PHP. Im willing to buy the script and send you the original one if you can make the improvements I need.
We discuss all the improvements in the face.
We are also ready to consider the option of writing such a script from scratch. If you can implement such or analogue.