Hello I want to share my Ureal project with a third part to fix some bugs and do some new features, what is the way to share these files but keep the IP (Intellectual property) for exmaplen the code, the assets with me, I will give them our company account so for exmaple not allowing the project to be build without a password or anything related.
So how studios protect there files with third part?
Hi! There might be some ways to “lock” your project like you want, which I’m not aware of, but I can give some general advices.
You can consider migrating the related parts that the third party should work on to a new blank project and sharing that project instead, if that’s possible.
When it comes to taking precautions against piracy and copyright infringement (if you have one, that is), I may not know it’s technical aspects, but I do know that the most crucial aspects are the legal ones! There’s no doubt in that it will always be possible to steal stuff no matter how good they’re protected, so what really matters is being able to claim your rights! With that being said, you can consider consulting an intellectual property attorney and designing an appropriate contract that fits your case to present to the third party.
Additionally, I must say that I didn’t quite get what do you mean by “giving them your company account”, could you clarify? Normally, version control systems such as Git or Perforce are used for collaborations and both have settings that can be adjusted to grant / restrict access to individual collaborators. (Note that this feature requires a fee on Git and Perforce is free up to 5 collaborators. It’s also important to mention that even if you have less than 5 collaborators, using Perforce would cost money due to the cloud storage service that you’d need to use alongside it, unlike the decentralized one on Git which is free up to 2GB. Azure is also free up to 5GB and AWS is up to 30GB but don’t be mislead, it also costs money on each upload so they will definitely require money eventually. Though if you choose to handle the maintenance yourself, you can avoid that cost by storing the project on your local machine.)
Hope this helps! 
If you’re actually talking about IP, you don’t have to do anything.
Unless you sign a contract that transfers IP rights of things to another party, you keep rights to IP that you create without doing anything.
If you’re talking about protecting the files so that they can’t physically make copies that they then use in another project, there’s also nothing you can do. If you give them access so that they can fix issues with them, they’d be able to make copies of them.
Generally through contracts and lawyers. To actually do anything if you suspect/know that someone is doing something they shouldn’t with your content generally involves suing them. Or at least threatening to sue them. If you don’t have the resources to do that, it’s sort of a moot point.