Cantrips not appearing

Hello. Apologies if this is user error; I did check the help pages first. My player character is a paladin and selected a feat that allows for additional cantrips. However, I see no way to add cantrips to my spellbook. Tavia, an NPC appears to have a similar problem. I asked Franz who reported an error. Deylan, another NPC, has spell slots and cantrips, but he did not automatically prepare them. I think I can work around by going to spellbooks, selecting “add spell” → “from SRD”, but this does not appear to be intended behavior.