rotating the tire won't seal it if the leak is at the valve or even the bead.
First off I'd take the wheel off and use soapy water to find the leak. If it is the valve put the valve at 6 o'clock and bounce it against the ground. That splashes the sealant up against the valve seat.
If it is the bead you have to do the old shaky dance. Most people skip that these days when doing tubeless since most of the time riding will splash the sealant around on the bead good enough. You can also lay the wheel on it's side using a bucket to help with sidewall leaks and to a leaser extent bead leaks.