I am programming three things, an API, an Android app, and a front-end web React app. The whole system will be sold to a company for money, I have no problem with them modifying the source code to fit their needs and making my system communicate with their APIs, but I don't want them to copy my system and give it to other companies.
I want this license to only allow them to do whatever they want with my source code only for their own uses, but not for selling it or sharing it with others.
Which license I should use?