So, there is some knowledge you gain from your career and this information is important and valuable because it save the client big money.
For example, for OTP verification with a mobile number, there exist many free services which client is unaware of. He thinks that all services are paid and I told them that there are some free services which I can integrate.
Now before the proposal has been accepted, he ask me what service am I going to use for OTP verification which I claim to be free and reliable? I am afraid he will get the information from me and use it with some other Freelancer.
How should this be tackled, should I pass the information without knowing if I will gain the proposal or dodge it?