On February 26th, USCIS updated its FAQs on H-1B Electronic Registration Process for the Fiscal Year (FY) 2022 H-1B cap filing season. The H-1B cap registration period will start on Tuesday, March 9th at 12:00pm (noon) (ET) and go through Thursday, March 25th at 12:00pm (noon) (ET).
Here is an excerpt from the updated FAQs, I have included the first two questions and answers from the web page:
H-1B Electronic Registration Process