CreditKarma is an Intuit product that, among other things, offers a high-yield savings account.
They are, essentially, promoting another of their products within the one you're using. Note the footnotes 1-4 (which aren't in your screenshot).
You would need to create a CK account if you don't have one, you'd essentially be opening a savings account with them. Whether or not this is a good idea depends entirely on where you're at in terms of building savings. If you want the money for immediate use, go direct deposit. If you're building savings and want to try to score some free money and don't mind opening another savings account to do so, then give the fine print a read-through, make sure they're insured, etc, etc.
Personally, I just go direct deposit and carry on with my savings plan, but that has as much to do with "I just did my taxes and don't want to read paperwork to open a new account somewhere else" as anything else.