FSRS-5 is still in alpha stage, so you could only use it via the custom scheduling script.
Here is the tutorial: https://github.com/open-spaced-repetition/fsrs4anki/blob/main/docs/tutorial2.md
Release files
- Scheduler: fsrs4anki_scheduler.js
- For Qt5 version: fsrs4anki_scheduler_qt5.js
- Optimizer: fsrs4anki_optimizer.ipynb
What's Changed
- A special case where "Ignore reviews before" won't work.md by @Expertium in #671
- Small clarification.md by @Expertium in #684
- Update tutorial.md by @Expertium in #685
- Update the workload/retention image.md by @Expertium in #687
- Retention -> Desired retention.md by @Expertium in #688
- Update the graph (again).md by @Expertium in #689
- update to fsrs-optimizer v5.0.9 by @L-M-Sherlock in #690
Full Changelog: v5.0.3...v5.0.4