I don’t think you can directly. The files are already on the (theoretically) lost device.
Remotely locking or wiping your device entirely would probably be the best method.
If you can’t do that, then as a minor step, maybe (after making a separate copy of your vault on a device under your control as well as making a back-up) delete all of the files in the synced vault, let the deletions sync to the remote vault, and hope the adversary tries to open your Obsidian before they make a copy of your data.
