My setup:

1. API service holding a bitcoind Full Node.
2. Client Wallet - I have no control over that system.

3. User application - Who gets the barcode for payments.

   • So, My API (1) only has the Receiving Address of the Client wallet (2).

The problem:

Let's say my client is a hotel, I want the API (1) to set the maximum fee for the transaction if the user (3) wants to get a room today and the minimum fee available if the user will set a reservation for two weeks from now.

Leading question:

Is it possible without any control over my clients (2) wallet?