Use File > Export > Zipped loop package. It writes one .zip holding the .flp and the samples the project uses, which is the file to put on a backup drive or send to someone. A bare .flp only stores where your samples were on your disk, so copied alone it opens on another machine with every sample missing. If you would rather keep a folder than a zip, File > Export > Project data files copies the samples, presets and plugin data the project uses into one folder you pick.

Back up an FL Studio project

• Zipped loop package (File > Export): the .flp plus its samples in one standard zip. Image-Line recommends it for archiving important projects.
• Project data files (File > Export): copies of every sample, preset and plugin data file the project uses, in a folder of your choice. Keep the .flp beside it.

Neither one carries your plugins. A project that uses Serum or Kontakt needs them installed wherever it is opened, and a missing plugin loads as an empty wrapper.

Version a project and roll back

File > Save new version (Ctrl+N) saves the project under a new numbered name: MyProj becomes MyProj_2, then MyProj_3. Every number is a full project you can reopen, which makes it the simplest way to keep the beat before a big change.

FL Studio also autosaves. In Options > File settings (F10), the Backup section sets how often (from never to every minute, and before risky operations such as adding a plugin), how many saves to keep before the oldest is replaced, and where they go. By default backups land in Documents\Image-Line\FL Studio\Projects\Backup, which the Browser shows as the Backup folder. File > Revert to last backup loads the most recent one, or open any older one from the Backup folder.

Send an FL Studio project to a collaborator

Send the zipped loop package, not the .flp. Tell them your FL Studio version and which third-party plugins the project needs. For a co-producer who only adds a part, a bounce of the beat plus the stems they need is often easier than the project.

Export stems for mixing or mastering

1. Route every instrument to its own Mixer track. Instruments sharing a Mixer track export as one file.
2. Choose File > Export > Wave file (Ctrl+R).
3. In the render window, tick Split mixer tracks. FL Studio writes one WAV per Mixer track; muted Mixer tracks are skipped.
4. Check Enable master effects under Miscellaneous. For a mix engineer you usually want it off, so master bus processing is not printed into every stem.

File > Export > All playlist tracks does the same per Playlist track instead of per Mixer track, from song start, from each track's start or for a time selection. Render from song start so every file lines up in the engineer's session.

Doing it in Aden

Aden's desktop app reads FL Studio projects on your disk, including the zips you already make.

• Your projects, listed. The desktop app finds .flp files across your machine and lists them on Home. A zipped loop package counts too: it shows under the name of the .flp inside it, so the producer who zips everything still sees their beats. On macOS, with Accessibility permission, Aden reads FL Studio's window title to tell which project is open, because FL Studio reads the .flp and closes it.
• Sync the project folder to a track (Max plan). Every save is pushed. A collaborator clicks Pull to get the latest files; a pull never overwrites their local edits, it saves the incoming file as a versioned copy beside theirs. Every synced file keeps its version history, downloadable from the track's Project files page.
• A check before you send. Send as a transfer zips the project folder into a link that expires in 30 days. When the folder holds little more than the .flp, it tells you to collect the samples first.
• Read the .flp on the web. The Project files page shows tempo, time signature, length, every channel with its colour and mute state, the plugins it loads (the real plugin inside each Fruity Wrapper, with its maker and VST2, VST3 or CLAP format), every sample path, and the patterns, notes and markers. FL Studio does not store a key, so key stays empty.
• Play it in the browser. Sampler channels and audio clips play your synced samples; Fruit Kick and Plucked! are rebuilt from their saved settings. Other plugins get a stand-in sound, and effects and automation are not played. Double-click a pattern to open its notes in a piano roll and download them as .mid.
• Edit and record together. Move or delete clips with everyone on the page; Save writes the change into the .flp as its next version and leaves every plugin, mixer setting and sample as it was. Vocal takes recorded in the browser land in an Aden Takes/ folder, named by the bar to drop them at.
• Feedback on the bounce. Export the beat and the desktop app notices it: named after a track you have, it offers it as that track's next version. Send a share link and people comment at a timestamp or on a section of the waveform, with no Aden account needed on a link with comments turned on. Send for review asks them to approve it or request changes.
• Stems on a version. Upload your Split mixer tracks WAVs to the version's Stems tab to line them up and play them under the mix.
• Aden inside FL Studio. The desktop app installs Aden as a VST3 plugin on macOS and Windows. Load it on the master to see the track's notes, lyrics and session without leaving FL Studio.

Sources: FL Studio manual, File menu, FL Studio manual, file settings and Backup, Image-Line support, exporting each track to a separate file. See also how other DAWs version projects.