TypeError: add() missing 2 required positional arguments

[NectDz]

Hello,I am new to parameters and I am having difficulties understanding my code does not work.

# Tables

Table_A = 0
Table_B = 0
Table_C = 0

# Seats remaining

seat_A = 4
seat_B = 6
seat_C = 2

def add(user_In,Table,Seat):
    for i in range(user_In):
        Table += 1
        Seat -= 1
    return(Table)

def sit():
    global Table_A, Table_B, Table_C, seat_A, seat_B, seat_C
    while True:
        time.sleep(1)
        # Showing Tabls
        print("\nShowing Tables\n")
        time.sleep(1)
        # Table A
        print("Table - A has -", (Table_A), "- people / -", (seat_A), "- seats remaining")
        # Table B
        print("Table - B has -", (Table_B), "- people / -", (seat_B), "- seats remaining")
        # Table C
        print("Table - C has -", (Table_C), "- people / -", (seat_C), "- seats remaining\n")
        time.sleep(1)
        # User Input
        user_In = input ("Which table would you like to choose: ")
        user_In = user_In.upper()
        if user_In == "A":
            Table = Table_A
            Seat = seat_A
            time.sleep(1)
            user_In = int(input("How many people are sitting? Max -" + str(Seat) + ": "))
            # Table A Returned
            print("\nTable - A has - " , add(user_In), "- in it")