thanks for the reply actually my itch.io email is 7studiodev@gmail.com.
And i used different mail for to purchase this software which was mention in other post.
I read itch.io help page. On that page it was mention that if you purchased something through login account then that purchased will be displayed in purchased items in your login account.
I also contacted support for the issue but got no result for this error.
But anyway thanks i am waiting for support reply.