I highly recommend BongoRX (https://bongorx.com/) if you have sleep apnea and can't deal with CPAP. The mechanism: it makes it a little harder to breathe out, which keeps your airways more open when you breathe in next.

The pictures on the website are a little misleading: it comes with a strap to keep the device in your nostrils, so they don't just fall out in the middle of the night.

FDA-approved, and does require a prescription...