I am currently playing a game with friends who have made their own custom list of Homebrew Feats to pick from, and because I am playing a Blood Hunter, I am using DnD Beyond for ease of use! All I need to do is put this one Homebrew Feat in so I can use it on my character, but I honestly don't know how to do so and would love to get some help!

So here's the Feat description:

...
Toughness v2
Similar to: Tough
Your hit point maximum is increased by an amount equal to twice your level. (This bonus increases as you gain more levels.)
You do not die on your third death saving throw failure; instead, you die on your fifth.
...

I'd love if anyone could lend me a guiding hand as to how I implement this as a Homebrew Feat so I can use it here on DnD Beyond, if possible.

For the first part simply use Tough as the template for your feat and it’ already be set up for you, you would just need to adjust it to 2 instead of 1.

For the second part you would need to create an Action without an activation type named “Additional Death Saving Throws” or something and add 2 limited uses to it to represent the additional 2 death saves. It won’t actually add additional death saves, they would have to be tracked separately under Features & Traits. I explained how to do that in the Feats FAQ #3: (https://www.dndbeyond.com/forums/dungeons-dragons-discussion/homebrew-house-rules/131411-a-homebrewers-how-to-faq).

Thanks, I will look into it! :D

Happy to help.

I don't have the Tough feat unlocked (because of the free rules), but I wanted to know how it works via Homebrew. What modifiers I need to look into in order to replicate the feat, just so I know how the Hit Points are getting calculated (that's all)

Modifier: Bonus->Subtype: Hit Points Per Level->Fixed Value: 2

Thank you so much