The IHI Reading Room is a nonpublic early collection prototype; access is granted after review. Tell the curator who you are and how you know this collection. If it’s a match you’ll get a single arrival link by email — no account, no password — and from then on the library knows you by name.
Prefer to just write? Email the curator directly — your name, how you know the collection, and where to reach you is all it takes. Either way, a person reads it.