What worked for me was vaping, especially as I made my own liquid. Slowly titrated the nicotine down until I was at 0 mg liquid, and from there it was easy to just stop as there was no physical addiction component anymore.
I know vaping gets a bad rap (undeservedly), but it was the only thing that worked for me. Helped not have to deal with the physical addiction and psychological addiction at the same time.
I still have my mod in case a relapse ever looms its head, but haven't needed it. If I ever have a truly awful day and need it, I would rather go back to that than a pack of cigarettes. My partner still vapes 0mg liquid from time to time. Neither of us ever touch nicotine anymore though.
EDIT: This should go without saying, but just in case I do not endorse anyone start vaping that doesn't already have a nicotine addiction they are dealing with. Even people who still actively vape and don't plan to stop will tell you that while it is almost certainly better for you than smoking, ideally you should only be inahling clean air.