No idea what "Brad's Deals" is, but you cannot get a discount offer unless you start from their website or access it somehow through them.
If you have a Discount Offer for Online, see this FAQ on how to get the discounts from your bank or other financial institution or work, etc.
https://ttlc.intuit.com/community/charges-and-fees/help/how-do-i-get-my-turbotax-affiliate-partner-discount/00/26509
I'm not familiar with that site either. Are you sure it's not just mirroring the already discounts that are currently being offered? i.e., Online Deluxe and Premier are currently $20 off for a Federal return; i.e., $40 for Deluxe and $70 for Premier. And Self-Employed is $30 off at $90. A state return is $5 off.
These early-season discounts will expire later on in filing season. Normally around March, but TurboTax says prices can change at any time if not locked in by paying in advance.
Typo corrected above. I meant to type "Self-Employed" for the online version; "Home and Business" is the desktop equivalent.
It isn't a code; it's just a link that goes straight from Brad's Deals to TurboTax Online. I've done my taxes through TT Online for 7-8 years, so my information just autopopulates, I guess. I tried to clear what I had already entered bc that's what the bot advised through Help. I've used Brad's Deals for many online discounts over the past few years; this is the first time I've had an issue.
Here's what happens when you click the Brad's Deals link (see tinyurl link below). It takes you to this landing page on TurboTax. But once you click "Sign In", you can't tell if anything's happened or not.
I have a habit of not clicking on links in a user forum so I didn't review the site you posted.
First of all, there are a lot of scam sites, so you have to be careful to do the homework first. If Brad's Deals is a legitimate site with a legitimate discount offer, then usually with affiliate partnered discount portals, you have to begin your return at the special discount page at the affiliate's website. That's how it knows to apply the discount.
If you already started at regular TurboTax portal, then you can try the following. This is what I tell folks who have started before they discover that their bank, travel club, brokerage, insurance agency, etc. offered a special discount portal.
Lot out of all Intuit accounts including this forum.
Delete all Intuit cookies and empty the browser Internet cache.
Close the browser and reopen it.
Go the special discount portal page. Do NOT sign into TurboTax account before going there.
Only sign in after you reach the discount page, and it asks you to log in.
And as I mentioned above, be sure it is a reputable legitimate site and offer.
If it's not obvious that you are getting the discount, you can go to the FILE section as though you were going to pay, and look at "Review Your Order."
Also, each time you work on your return, go back to that same special portal website to sign in and eventually pay/file the return.