Select an ad account, paste a CSV (headers: email,phone), and upload to your custom
audience via the `/facebook/audience/upload` endpoint. The service will reuse your stored
access token, create or reuse the audience, and hash identifiers before sending.
Redirects to /facebook/auth and comes back here after OAuth.
Ad Accounts
Upload CSV
Override stored default by choosing a specific account.
Pick the stored audience to reuse.
Create a new audience for this upload (name optional).
Choose a CSV to upload directly, or paste below (not both).