You can register interest for a closed beta key starting 2019/01/31, until the end of beta.
UPDATED with Schedule:
KurtzPel Global CBT Key Distribution Date: Feb 13th 2019
KurtzPel Global CBT Schedule: February 20th, 2019 PST ~ February 24th, 2019 PST (5 Days)
You will receive 2 beta keys if you apply through main website. Beta keys will be sent to the email you enter with. There will be an announcement when the keys get sent out on KurtzPel steam and facebook pages. (Make sure to check spam folders too, it might be there.)
You can apply for CBT key here: