Depends.
If you are a nasal snorer, sometimes steroid sprays will help, sometimes nasal surgery.
But most people are palatal snorers… Weight loss and less alcohol help many people. A few get helped by devices linked to here already.. Some people are helped by palatal surgery (UPPP) but the success rate is not brilliant and is generally only done privately.
Ear plugs can be relationship savers. Also there are some people who can sleep through it, and others who can’t. My ex-wife could, and so can my Partner now. But the one in between… despite being a player of the nasal trombone herself… found it a real problem.