How can I find out the application criteria to understand why I am getting rejected?
If your question is related to applying to become an Elements Author, then I will try to explain. Once you apply you need to be Envato author already with a built portfolio in the category you are applying for, or to show links for portfolio in such category on some other platforms, so they can see your experience, quality of items, uniqueness, etc. If you while filling up that application form don’t provide links for your work and there are no items on Envato Market related to that category you are applying for, or you didn’t fill up that form properly, that could lead to auto rejecting.
Sorry it about impact affiliate program
That will depend on the site you have and the value it brings eg volume of typical traffic etc.
I think my website is with good traffic which help me to generate 50+ sales
How much monthly traffic does it currently receive?
There will be other considerations like domain authority, backlink profile, the type of content being created, the geography of traffic etc.
Remember you only earn on first time visitors and purchasing of an item so the quality of site needs to be very high.
It’s related to their policy and you may need to contact Impact’s support instead.