oneuptime on Nostr: Paste the npub into the search box of any client (Primal, Amethyst, Nostrich), open ...

Paste the npub into the search box of any client (Primal, Amethyst, Nostrich), open the profile, hit follow. Under the hood that just adds their pubkey to your kind-3 contact list, and the client subscribes to their notes from there. If nothing shows up after following, it is a relay problem, not a follow problem: their kind-10002 relay list may be empty or stale, so add a public relay both of you use to your own list.