User Agent is: Mozilla/5.0 (Linux; Android 9; SAMSUNG SM-A205F Build/PPR1.180610.011) AppleWebKit/537.36 (KHTML, like Gecko) SamsungBrowser/9.0 Chrome/67.0.3396.87 Mobile Safari/537.36.
the 300h for the certification come from an estimate of 50h for the challenges and 50h for the various projects
depending on how much effort you want to put with it, and how muu familiarity with all the concepts you have now, it can be as low as a couple of hourse
just take the time you need to make something that passes all tests and you would be happy to say you made yourself
the curriculum is thought to be done in order
JavaScript is not present in this crrtificate curriculum
JavaScript is not needed to complete all requirements