I'm trying to submit my first longplay to the site, but while I was trying to submit it, I saw the "Longplays Source: Please either provide a Longplays file or a URL" and I'm totally confused, because it says "Max. file size: 1MB / Allowed file types: .pdf .gif .jpg .png .zip .rar .tar .bz2 .7z". But my longplay is 4:24:57 and 36.78GB. What do I do?

1. You gotta be in the Longplayers group (contact admins)
2. Create new submission in the "Submission Status" page.
3. Once recording/encoding done, upload the video and .sfv file on FTP server. Read this guide for that - https://longplays.org/infusions/forum/viewthread.php?thread_id=1914&pid=4421#post_4421
4. Change submissions status to "Submitted for approval" and wait for admins to approve/decline your longplay.

Atleast that's how I am submitting longplays since the beginning.

I guess you could also upload your longplay on some site and provide the URLs for that. I'd not upload it on youtube or similiar site, because these sites re-encode your video into streamble bitrate and format, so it decrease quality of the video. Archive.org is what this site use to archive all longplays, so I'd use that.

As far as I know, only admins have access to Archive.org uploading privileges (and submit the stuff right away). So the only official way for new submissions is by uploading your .mkv/.mp4 and .sfv files on the FTP server.

The review and process period normally takes between 1-3 weeks, depending on the videos' file size. That is why higher end stuff can take even more than a month, since Archive.org sometimes refuse to fully upload things without giving errors.

ftp server?

FTP server: cassiopeia.solit.se

Username and password is 'upload' for everyone to submit new longplays.