There seem to be different ideas as to which side has the right to choose the notary. As a precaution, some sellers call to inquire about my capacity for notarization orders in the event that the buyer does not have his own notary public. Because then you would like to come to me. Here it is assumed that primarily the buyer selects the notary. On the other hand, sellers are calling who have 20 apartments for sale at once and don't want to go to a different notary for each contract. Here the buyer is not asked at all, but the seller decides the notary and then all contracts are notarized there.
In fact, there is no legal requirement as to who appoints the notary.
The fact that the buyer usually bears the main costs of the contract (except for the costs of clearing the seller's old land charges, etc.) and thus also the notary costs speaks in favor of a selection by the buyer. Intuitively, some people follow the old principle "whoever pays, orders." The fact that the buyer can choose the notary is not questioned here at all, but simply assumed.
However, this is not mandatory. In the end, the seller decides whether, at what price and under what other conditions he wants to sell his property. If the seller wants the notarization to take place at a particular notary, he can pretend that he will not sell otherwise. There is nothing wrong with that, so that in the end the seller has the last word (at least if he is not forced to sell quickly for external reasons).