If you already have some videos recorded and you want to bring to NeetoRecord then we consider that "external video". The free plan of NeetoRecord doesn't allow you to upload any external video.
The "pro" plan will allow you to upload external videos.
Once you upload your video and then if you downgrade your plan to a free plan then also the uploaded videos will continue to function properly forever. Once a video is "in" NeetoRecord then it will continue to work.