Board Thread:Questions and Answers/@comment-45048319-20200214043408/@comment-35088630-20200214044222

1) Go to the game's page in your library and select the little cog, or right click it in the list, and go to properties. From there, select the "betas" tab, and switch to Experimental.

2) Subnautica Below Zero has it's own wiki, and it's suggested you talk about the game there rather than here.