Transfer my istop movie into imovie

Argghh help please. Ok I am a newbie. I have made my first effort at a stop motion picture I now want to get it into iMovie to edit it. I am working on an iPad 12.9” pro. I just don’t seem able to move the movie from A to B simply. I have tried export to I Movie but no luck it seems to send but nothing arrives I have tried via iCloud though it can be seen it is greyed out and unresponsive I have tried through file system but same as iMovie response. I don’t have another device to run iTunes. Having come from a PC background surely it’s got be possible to transfer files between two apps on the same machine simply and directly - especially two apps so intrinsically linked . Any chance of a dummies click by click guide to help me - please don’t assume any apple type knowledge. Thanks in advance John h