Can some please tell me what's wrong with my code

Hi I wrote the code arithmetic arranger in Pycharm and then used it in replit
but it is failing 7 tests out of the ten can you please tell me what I am doing wrong

def arithmetic_arranger(problem, answer=False):
    op = []
    num = []
    var1 = []
    for i in problem:
        x = i.split()
        var1.append(x)

    for i in range(len(var1)):
        op.append(var1[i][1])
        num.append(var1[i][0])
        num.append(var1[i][2])

    # print(var1)
    # print(op)
    # print(num)

    def max_of_digits(m):
        return max(len(var1[m][0]), len(var1[m][2]))

    ans = ''
    an = ''
    s = ''
    k = ''
    h = '-'.rjust((5 + max_of_digits(0)) - (max_of_digits(0)))
    x = h + '-' * (max_of_digits(0) + 1)

    if len(var1) < 6:
        if '/' not in op and '*' not in op:
            pass
        else:
            return "Error: Operator must be '+' or '-'."
    else:
        return 'Error: Too many problems.'

    for i in range(len(num)):
        if num[i].isdigit() and len(num[i]) < 5:
            continue

        elif len(num[i]) >= 5:
            return "Error: Numbers cannot be more than 4 digits."

        elif not num[i].isdigit():
            return "Error: Numbers must only contain digits."

    for i in range(len(var1)):
        if '+' in var1[i]:
            y = int(var1[i][0]) + int(var1[i][2])
            ans += str(y).rjust(6 + max_of_digits(i))
        elif '-' in var1[i]:
            y = int(var1[i][0]) - int(var1[i][2])
            ans += str(y).rjust(6 + max_of_digits(i))

    for i in range(len(var1)):
        s += var1[i][0].rjust(6 + max_of_digits(i))
        r = var1[i][1].rjust(6 + max_of_digits(i) - (max_of_digits(i) + 1))
        k += r + var1[i][2].rjust(max_of_digits(i) + 1)

    for i in range(1, len(var1)):
        x += ' ' * 4 + '-' * (max_of_digits(i) + 2)
    # print(s)
    # print(k)
    # print(x)
    if answer:
        an = ans
    else:
        an = an
    u = s + '\n' + k + '\n' + x + '\n' + an
    return u

What error are you getting exactly?

I don’t know how to show it here so I am pasting the link

https://replit.com/@HarishKukka/boilerplate-arithmetic-formatter-10#main.py

Can you please share the challenge link?

is the challenge link https://replit.com/github/freeCodeCamp/boilerplate-arithmetic-formatter