Brokerage agreement - House purchase through broker - Broker commissions

Hello everyone,
we are currently planning to buy a house, or rather we are just waiting for the bank's go-ahead to then sign the contract for an already found house.

The found house was offered through a broker. He has now sent us a brokerage agreement ... so that he, of course, receives his entitled commission.

"The client commits to paying a commission of ... from the total economic value ... upon conclusion of the proven or mediated contract," etc.

So the commission is only due when the notarized purchase contract has been signed by all parties, am I understanding correctly?!

"The commission is to be paid within 14 days of the invoice date"... What is the invoice date? The purchase contract?

I hope someone can help me at short notice and I already say thank you in advance.

Yes, correct. After the notary comes the invoice. The contract is his "success".

"The commission is to be paid within 14 days from the invoice date"... What is the invoice date? The purchase contract?

The date on the broker's invoice.

The date on the broker's invoice.

And it only comes after the signature in the notary contract.

Thank you, then I can confidently sign the brokerage contract beforehand.