Transfer captured video to iphone camera roll

First time here, so please excuse my lack of familiarity with this forum.

I would like to transfer (or copy) a captured video to the camera roll of my iphone (iOS16).

The video is captured by RVC game and is in a mpeg format.
I tried to upload it to itunes, but iTunes will only accept a jpeg.

Apparently I need someone to guide me as if I were a complete newbie (3rd grader).

A .jpg is a still shot like a portrait. It is not a video. You need to convert the file to a format that your iPhone takes. We do have Replay Converter that does this. Also, do check out our videos under support.