API implementation for our site to login - PhP & wordpress

We use a web application for service a travel website. They have introduced a few lines of API for single sign in to their site. Our site is in wordpress. We need someone with Php or Java or C# skills (we prefer Php) to implement the code in our side so we can take the benefit of the new feature to access the target site. Basically the API can let us to do a single sign in and the code (the example) we have been provided is only 17 lines but we want to make it like a plugin so it will be easier for us to implement. So we want someone to be familiar with the whole process and work with us until the project is fully delivered. You should have previous experience with php coding, API implementation, and wordpress. You should have good English communication skills and RELIABLE internet access!