I have a problem with using Json to save player data (they are not security enough)

So i am working on a individual project and when i finish coded player data save system I found a problem that they can looking for the file that contain player data information and messing up with it like change the money vaule
Level vaule, time and date system vaule, tools unlocker vaule,…..
I dont want to save player data with cloud save or something i just want to save it with the game file
So i want to ask how to make my player data save system more security?

 

Encrypt it then, there are tons of resources online.
Although if it's a single player game, you might not want to. Some players do get a lot of satisfaction out of messing about the values and seeing what they result in

 

If you're concerned about the user 'hacking your save files,' don't be. There's nothing you can do. Nothing is secure, it is not your computer, it is the user's computer. If it must be secure, store it on your own server and have the user connect to download it. Anything else is a waste of your time. Work on your game instead.

Remember, it only takes one 12-year-old in Finland to write a script to read/write your game files and everybody else can now use that script. Most likely nobody will care enough about your game to bother, so you're safe.