Please find the answers inline:
1. How can reset / change user password by email id in UserService app42 cloud API?
-> For resetting a password, you can use our ResetUserPassword API where an automated email will be generated on your registered EmailId with a new random password and for changing the password, you can use Change Password API, Change the password for a user based on their username, only if the old password is valid.
2. I have forgot password feature in my app so how I can implement in Corona SDK using app42 cloud APIs or any other ways?
-> You can use our ResetUserPassword API.
3. If I use "Reset user password" API of app42 cloud so where I can get changed password?
-> An automated email will be generated on your registered EmailId with a new random password.
If you have any other concern please do feel free to reach out to us, we will be happy to help you.