Das Formular:

<form method="post" asp-controller="Home">
    <input asp-for="Movie.Id" name="Id" hidden="true" /> 
    <input type="submit" name="submit" value="Delete" class="btn btn-primary" />
    <input type="submit" name="submit" value="Cancel" />
</form>

Die Funktion:

public IActionResult OnPost(Int32 Id, String submit){
            if (submit == "Delete"){
                Int32 Result = RP.MovieDB.Movies.Remove(Id);
            }
            return RedirectToPage("./Index");
        }

Quelle