When you connect Pinterest to Postier, you grant us permission to create and schedule Pins on your behalf. Pinterest only gives that permission to apps working with Business accounts. Personal accounts simply don't have the option to authorize a tool like Postier.
A Business account is free, takes about a minute to set up, and you can convert your existing personal account without losing any boards or Pins.
Once you connect your Business account, Postier can publish your product Pins automatically — that's the whole point of the tool. If you've connected a personal account by mistake, see our step-by-step guide on creating or converting to a Business account.