Entertainment Weekly:

More entertainment fodder for your shelter-in-place: Star Trek: Picard is now free to non-subscribers to CBS All Access.

Or, put more accurately: Non-paid subscribers. You’ll still have to sign up for the CBS streaming service to watch the show, but now there’s a coupon code that unlocks Picard: “GIFT.” The will unlock a one month free trial which includes all shows on the service (so if you want to check out Star Trek: Discovery or old episodes of Next Generation, you can do that too).

There are nine episodes from the show’s first season available now, and the season finale drops on Thursday.

As noted in the comments section:

There’s no way to sign up without giving them your credit card info and having to manually cancel the subscription in the future. It’s no different than any other free trial.