If you join the discord server all test builds are in there. You can also become a tester and play the update that way. When its done being tested i imagine it will be uploaded to sidequest like before.
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Are you in the discord? You can ask questions in there. You can either post some gameplay to YouTube and earn temporary tester or you can donate $10 to earn permanent tester. You will need to post videos pretty regularly to keep your access to the test builds if you choose that option. Feel free to ask questions in the discord. A bunch of people in there are always willing to help and it's pretty active most of the time.