Hi there,
Apologise for the delayed response.
You are more than welcome to Register as a Developer here.
Select the Registration form, answer the questions and write out a small case as to what the function of your app is, how it will be built and the benefit for the user.
You will be applying for the free, OPEN access licence Developer licence which can get you setup to run tests as you need.
Hope this helps and if you have any further questions, please feel free to create a Support ticket using the same link above.
Kind regards