https://www.cid.army.mil/assets/docs/Direct-Accession-Take-1_2018.pdf
Read that. Go to the CID website and read some more there. Especially the “Join CID” page, for Direct Accessions focus on the section that says something like “Not in the Army yet? No problem!”
I think goarmy.com mentions the program under the 31D MOS. If I remember correctly, it just restates the basic info from the CID site though. If you want more answers about what it is, I don’t know what to tell ya. It is what it says it is.
For the application, contact a recruiter. This is the “fun part” because it’s highly likely they won’t know dick about the program and will look at you weird for asking about it. If they don’t know about it, push them to contact their battalion to see if someone there knows about it or to find someone who knows about putting the packet together. Don’t let them talk you out of at least putting the packet together and applying just because they’ve never done it before and think it might be a lot of work. It’s not that much work for them, and it’s definitely worth it for you if you can get accepted.