There are a few ways of doing it, which one you use depends on how you want to user your system.
In the GUI:
If you go to the main menu Settings page you’ll find a section called “Update channel”.
Right now you’re probably on the “beta” channel which is the most stable. If you change that to the “experimental” (next most stable) or “canary” (least stable) channel then you’ll see other (and more frequent) updates.
“Over” install
If you’d prefer a fresh “base version” install rather than an in-GUI update, you can download the appropriate installer from Releases · duplicati/duplicati · GitHub.
Manual:
You can use some of the steps in Downgrading / reverting to a lower version to manually download a newer version (say 2.0.3.5) and unzip it into your updates folder.
Restart Duplicati and it should find that version and run it.
I can confirm OneDrive v2 is in versions going as far back as 2.0.3.4 canary, but I can’t downgrade to 2.0.3.3 right now to check if it’s in there or not.
If you do decide to shift to canary versions to get access to OneDrive v2, I’d suggest not going past version 2.0.3.5 as the later versions introduced a lot of code changes that haven’t been fully ironed out yet…