[CodeCanyon] Your item, MultiShop POS with Inventory, has been rejected

I am new in this platform.I have tried to submit " MultiShop POS with Inventory" PHP script two times in codecanyon . But after Submission, I received following mail from codecanyon:

Thank you for your submission. We have completed our review of “MultiShop POS with Inventory” and unfortunately we found it isn’t at the quality standard required to move forward, and you won’t be able to re-submit this item again.

We appreciate the effort and time you’ve put into creating your item. And we’d be happy to help make sure your next entry will meet our submission requirements. Here’s our advice:

Visit our forums and ask fellow authors for feedback. Our helpful community will be glad to lend a hand.

Check out this Help Center article to understand why and how items get rejected.

Remember you can get help, in the form of tutorials or skilled professionals, on Envato Tuts+ and Envato Studio.

My demo url is: https://youthfiresoft.com/multishop/
Username: youthfireit
Password: 123456

Hope, I will get support from the experts.

Hello!

Design is not good. It does not look modern. You need to completely redefine template.
You cannot go on without this.