As most of the Drops Campaign setup is all handled by hand through the Twitch Dev Console there are no endpoints to either get, create, or update, Drops Campaigns.
It’s unfortunate, and the only feature request on UserVoice for this sort of thing seems to be https://twitch.uservoice.com/forums/310213-developers/suggestions/38050441-drops-campaign-api which is a few years old and doesn’t even include a description on use case, so if it’s something you’d like to see I’d suggest voting for that and commenting with what your use case would be.