Access to stored files

So i am in little problem. I had wps office installed on iphone. I got some docx and pptx in whastapp and mail, then i opened them through wps office. But then i uninstalled wos office. And when again i installed it, i said no documents,. 1) did my documents with uninstallation also got deleted??? 2). If not then how can i get them again in wps office? 3) i know documents may be somewhere saved in storage. But can't be accessed. 4) i don't wanna open them from mail or whatsapp and also don't wanna download them again.

TIA.