the skill comes with some backgrounds and the Druid class. Hermit being the the 2024 background, the kit itself is listed as other tools. However if it is missing, from the creator it's just a bug that needs to be fixed, and there is a thread over in site bugs for that.
Note to access Hermit you need access to the 2024 players handbook, while the tools are listed in the PHB they are included in the free rules too, mostly due to Druid being in the free rules.
It's not listed as a choice in any of the 2024 tool or skill options for backgrounds.
ok... so how are you trying to add it?
Are you playing a Druid, or are you taking the HermitBackground? In order to gain it, you need a class or background that includes it. It is not an option for any other class but Druid, and it is not an option for most backgrounds in 2024 only a Hermit has access to it. If you use legacy or partnered content the following list of backgrounds include it:
Hi was trying to make some characters but I can't find herbalism kit profecy not under crafter, skilled or select a tool. Do they no longer exist?
the skill comes with some backgrounds and the Druid class. Hermit being the the 2024 background, the kit itself is listed as other tools. However if it is missing, from the creator it's just a bug that needs to be fixed, and there is a thread over in site bugs for that.
Note to access Hermit you need access to the 2024 players handbook, while the tools are listed in the PHB they are included in the free rules too, mostly due to Druid being in the free rules.
https://www.dndbeyond.com/forums/d-d-beyond-general/bugs-support/204813-players-handbook-issues-and-support-thread
It's not listed as a choice in any of the 2024 tool or skill options for backgrounds.
You can always add it manually by clicking on the Proficiencies & Training cogwheel on the character sheet itself.
Playing D&D since 1982
Have played every version of the game since Basic (Red Box Set), except that abomination sometimes called 4e.
ok... so how are you trying to add it?
Are you playing a Druid, or are you taking the Hermit Background? In order to gain it, you need a class or background that includes it. It is not an option for any other class but Druid, and it is not an option for most backgrounds in 2024 only a Hermit has access to it. If you use legacy or partnered content the following list of backgrounds include it:
Witherbloom Student
House Agent (Jorasco)
Gruul Anarch
House Agent (Vadalis)
Otherwise it is not an option you can take.
Note there is one exception, but I doubt that you are using the "make your own background option" from the 2014 DMG.
edit: added links
You could also take the Skilled feat:
“You gain proficiency in any combination of three skills or tools of your choice.“
You should be able to choose the Herbalism Kit through that.