I have an account and got to the booking and appointment page but things are not clear

There is a list of different visa types

I was looking for ILR option but it doesn't say ILR on the list. I see FLR SET(M), Tier 1, Tier 2, etc.

But no ILR! It's really confusing - you'd think they would make it easy considering the amount of cash they are going to take from me.