Because the utility model only protects the product, not the method.
If you want to apply for a patent, you should be careful not to publish articles about it before applying, otherwise it may affect the novelty of the patent.
Then, if it is not realized, you need to think clearly about every step to ensure that it is really feasible, and record the whole scheme in detail in the patent specification to avoid the problem of insufficient disclosure.
It is best to find a patent agency, so that the process of application and reply notification will be much standardized, and the problem of patent rejection due to ignorance of patent laws and regulations will be avoided.
It is not safe to sell directly because:
Others won't promise to give you money until they see your skills;
But after you show it to others, whether you can get the money depends on your own ability.
Personally, I think it is not very easy to operate.