A Meta Graph API Page Token that can publish posts to a Facebook Page.
Facebook Pages run on the same Graph API as Instagram, but the token you need is a Page Token, not a User Token. You'll create a Meta App, walk through OAuth as yourself, then trade your User Token for a long-lived Page Token that never expires.
If a Page already exists, skip this. The Page is the thing you'll post TO — it's separate from your personal profile. A human gets a profile; a business, project, or product gets a Page.
Create a Page
On facebook.com: Create (top right) → Page. Business name and category is all the API actually needs. Profile photo, cover, About — skip them; they're for humans, the API doesn't read them.
Next: request pages_manage_posts + pages_read_engagement, complete OAuth on localhost:8765, swap the short-lived User Token for a 60-day long-lived one, then call /me/accounts to pull out a Page Token that doesn't expire. ~10 more clicks.