what mean: "Provider must forward an invoice to Unity for the balance" ?

Hi, I'm are a total noob here and english not is my first languages.

I have read the ASSET STORE PROVIDER AGREEMENT and it said:

4.3.1 The parties agree that any balance in favor of Provider will be calculated by Unity and communicated to Provider within the first ten days following the expiry of each calendar quarter for the immediately preceding calendar quarter. No later than ten days following Providers receipt of the calculated amount in favor of Provider, Provider must forward an invoice to Unity for the balance (provided that this balance is at least 250 USD). Unity will pay such balance above USD 250 to Provider no less than 14 days following Unity's receipt of the invoice.

What is mean "Provider must forward an invoice to Unity for the balance"?

Can someone explaint it to me, please? I want know precisely what I must do. Is my first time and this point is obscure for me.