Yes, you could take the AZ-900 certification exam from home, or from a test canter suiting your comfort. The only requirement is that you have to meet their certification exam requirements, as the exam is proctored. So, it is important to check these requirements, before taking the exam. At the time of writing, Pearson VUE is the official testing company for Azure certifications. If you wish to get AZ-900 certified, then I would recommend you to check out the Microsoft Azure Fundamentals training from Intellipaat. Also, have a look at our YouTube video on Microsoft Azure Fundamentals Certification.