The short answer is complex. DICE never included an official "Conquest vs. AI" mode like in Battlefield 2042 or the classic Battlefield 1942 . Yet, the modding community (specifically the "Venice Unleashed" team) has been working on a solution.
But a stable, "download, click, play, 64 bots, horses, planes, dreadnoughts" experience? battlefield 1 offline bots mod work
The Venice Unleashed team deserves applause for trying to break Frostbite's limitations, but until they release a public, one-click installer, your best bet is to either stick with the human players online or join the 2042 Solo mode. The short answer is complex