Call
You've got to build a community! That starts with building up your social media platforms, engaging with your audience, and participating in events like book signings. A lot of local bookstores will be open and they'll typically be on the hook to buy 10 or 20 books. Make sure you've got good public relations and do press releases as you prepare for these events—from there, get that manager to share that info with another manager in a nearby store. Continue to do that, and then eventually talk to them about stocking your book in multiple locations.