Can’t upload image via submitting custom post from frontend

I have an issue with submitting custom post from frontend with image. I have a form with post title, description and image, that should be featured image of the post. So when user submitting post, it actually creates with title and description, but without image, even in media library the image doesn’t appear. Here is my form:

Wp_List_Table is showing as no class found named wp list table

I Developed a plugin I wanted to show data in wordpress table in admn area for which Wp_List_Table clas is used to do that I tried to use this but the problem is that it not being able to properly implement something is wrong I do not know what this is wrong which is causing this error so now let me define what exactly is the problem First let me post the code of my plugin along with file path