Connect 4 board

[Radroad]

I made a 3x3 connect 4 board game now I want to expand it so Its an actual connect 4 game and not tic tac toe. I want to make the board 5x7 please help

from random import randint
def initialiseBoard():
    print('Following is the board and the respective positions.\nEnter the row and column separated by a space to play.')
    board = [['' for x in range(3)] for y in range(3)]
    for i in range(3):
        for j in range(3):
            print('[{0},{1}] '.format(i + 1, j + 1), end='')
        print()
    return board
def inputBoard(board, turn, play):
    print()
    if play == 'player':
        if turn % 2 == 0:
            print('Player X What move do you want to make? Answer as row (vertical) column (horizontal) or save game or load game ')
        else:
            print("Player O What move do you want to make? Answer as row (vertical) column (horizontal) or save game or load game ")
        x, y = map(int, input().split(' '))
        if x > 3 or y > 3 or x < 1 or y < 1:
            print("Enter valid position")
            return True
    if play == 'ai':
        # print('Computer entered its position ')
        while True:
            x = randint(1, 3)
            y = randint(1, 3)
            if board[x - 1][y - 1] == '':
                break
    i = x - 1
    j = y - 1
    if board[i][j] != '':
        print("Enter row and column that hasnt already been chosen.")
        return True
    if turn % 2 == 0:
        board[i][j] = 'X'
    else:
        board[i][j] = 'O'
    return
def checkWin(board, ch, play):
    for i in range(3):
        if board[i][0] == ch and board[i][1] == ch and board[i][2] == ch:
            if play == 'player':
                print('Player ', ch, ' Wins!')
                return True
        if play == 'ai':
            print('Computer wins!')
            return True
    for i in range(3):
        if board[0][i] == ch and board[1][i] == ch and board[2][i] == ch:
            if play == 'player':
                print('Player ', ch, ' Wins!')
                return True
            if play == 'ai':
                print('Computer wins!')
                return True
    if (board[0][0] == ch and board[1][1] == ch and board[2][2] == ch) or (
        board[0][2] == ch and board[1][1] == ch and board[2][0] == ch):
        if play == 'player':
            print('Player ', ch, ' Wins!')
            return True
        if play == 'ai':
            print('Computer wins!')
            return True
    return False
print('AdjoinTheSpheres Main Menu')
while 1:
    print("1) New Game (2 player)")
    print("2) New Game (1 player vs computer)")
    print("3) Exit Game")
    choice = input("Select Option from the Menu: ")
    if choice not in ['1', '2', '3']:
        print("Please enter valid option")
        continue
    else:
        break
while (choice != '3'):
    while True:
        board = initialiseBoard()
# print("X plays first")
        turn = 0
        while turn < 9:
            if choice == '1':
                if (inputBoard(board, turn, 'player')):
                    continue
            elif choice == '2' and turn % 2 == 0:
                if (inputBoard(board, turn, 'player')):
                    continue
            elif choice == '2' and turn % 2 == 1:
                if (inputBoard(board, turn, 'ai')):
                    continue
            for i in range(3):
                for j in range(3):
                    if board[i][j] == '':
                        print('[ ]', ' ', end='')
                    else:
                        print('[', board[i][j], ']', ' ', end='')
                print()
            if turn % 2 == 0:
                if (checkWin(board, 'X', 'player')):
                    break
            if turn % 2 == 1 and choice == '1':
                if (checkWin(board, 'O', 'player')):
                    break
            if turn % 2 == 1 and choice == '2':
                if (checkWin(board, 'O', 'ai')):
                    break
            turn = turn + 1
            if turn == 9:
                print("Its a draw! Everybody sucks!")
        x = input("Want to play again? Press 1 for yes, anything else to exit out.")
        if x == '1':
            break
        else:
            print("Thank you for playing!")
            exit()
        choice = input("Select option\n1)Play against another player\n2)Play against computer\n3)Exit\n")