Your customer quotes and invoices carry no PaintClarity branding. That is true on both the free plan and Pro, and there is nothing to remove.
If you would like to support PaintClarity, you can choose to show a small “Powered by PaintClarity” credit at the bottom of your customer documents. Turn it on under PaintClarity, Business, Quote and Invoice Branding. It is off until you switch it on, and you can switch it back off at any time. Your own logo, name and address are unaffected either way.