Your question unfortunately is missing a lot of important context. What GUI platform are you using? WinForms, WPF, Blazor, .NET MAUI..?
Is it even .NET?
Other than that, approach the task the following way. The buttons have a on click event. Clicking invokes an event handler for the button click. The event handler is some method/function. It is responsible for e.g. sending data. So, you just add logic to that method to update the relevant UI item to display information that you want