TypeError: list indices must be integers or slices, not tuple (Python 3.11)

I am trying to create a noughts and crosses game in python, and I got an error in the bold text area in checkGridRow(). This is where I want to check if the game has been won by any player by checking for "XXX" or "OOO" in a horizontal row. At the end of the code, I use the parameter of "position" as the Y position in the grid and so pass 0, 1 and 2 to check all the rows. However I have run into the error in the title, and I don't know what it means despite searching, as I have no tuples in my code (as far as I can see). I am a beginner so please try to explain in relatively simple terms, thank you for helping

grid = [["_","_","_"],["_", "_", "_"],["_", "_", "_"]]
game = True


def checkGridRow(position):
    n = 0
    ***if grid[position,n]!= "_":***
        if grid[position,n]== grid[position,n+1] and grid[position,n+1]==grid[position,n+2]:
            game = False
    return game

def checkGridCol():
    tempList = ""
    c1 = [grid[0,0], grid[1,1], grid[2,2]]
    c2 = [grid[2,0], grid[1,1], grid[0,2]]
    if not any("_" in i for i in c1):
       for var in c1:
           tempList+= var
       if tempList == "XXX":
           game = False
       elif tempList == "OOO":
           game = False
    return game
            
        
def PlayerTurnX():
    column = int(input("enter column >> 1,2,3: "))
    column = column -1
    while str(column+1) not in "123":
        column = int(input("enter column 1,2,3: "))
        column = column-1
    
    row = int(input("enter row >> 1,2,3: "))
    row = row-1

    while str(row+1) not in "123":
        row = int(input("enter row >> 1,2,3: "))
        row= row-1


    
    if grid[row][column]=="_":
        grid[row][column] = "X"
    elif grid[row][column]!= "_":
        print("Space taken")
        row = int(input("enter row >> 1,2,3: "))
        row = row-1



    for item in grid:
        print(item[0]+" "+item[1]+" "+item[2])
    



def PlayerTurnO():
    column = int(input("enter column: >> 1,2,3: "))
    column = column-1
    while str(column+1) not in "123":
        column = int(input("enter column >> 1,2,3: "))
    
    row = int(input("enter row:  >> 1,2,3: "))
    row = row-1


    while str(row+1) not in "123":
         row = int(input("enter row:  >> 1,2,3: "))
         row = row-1

    if grid[row][column]=="_":
        grid[row][column] = "O"
    else:
        print("Space taken")
        column = int(input("enter column>> 1,2,3: "))
        column = column-1
        n=n-1



    for item in grid:
        print(item[0]+" "+item[1]+" "+item[2])



while game:
    print("Player X, your turn!")
    PlayerTurnX()
    checkGridRow(0)
    checkGridRow(1)
    checkGridRow(2)
    checkGridCol()
    print("")
    print("")
    print("Player O, your turn!")
    PlayerTurnO()
    checkGridRow(0)
    checkGridRow(1)
    checkGridRow(2)
    checkGridCol()

I've tried searching the error message and still cannot figure out where the tuple is, as far as I know tuples look like this myTuple = (x, y, z)

grid[position,n] is not the correct syntax for accessing a nested list.

Use grid[position][n] instead.