3GPP 23.501 v20.2.0 — the document's own text
6.3.18 5G-EIR discovery and selection
Taught in 6. How one function finds another (The 5G system architecture, in depth).
A consumer NF of the 5G-EIR performs discovery of 5G-EIR using either configuration or NRF as specified in clause 6.3.1. The network is configured with the 5G-EIR to serve the PLMN of the NF consumer requesting the 5G-EIR service, i.e. no roaming interface is defined.
The 5G-EIR selection function in NF consumers is independent of Access Type.