I’ve signed lots of NDAs for bike inventions. About half the time, I can then advise the inventor that their invention has already been invented*.
It’s pretty unlikely you’ll find a company to just buy or license the idea from you, so you have two choices – go into mass production yourself, or go into small batch production yourself.
First option requires lots of investment, and definitely you would want to get it patented/registered. Second option, just accept you have a limited window before (if it’s a good idea) someone rips it off, so make hay while the sun shines then get out with some profit and minimal risk.
*the best was the guy who spent £20k on designs, injection mould tooling etc for his radical new invention – a license plate holder to attach to bike racks.