How to choose the element that we need for Crosstab Table?

Question

I have a dataset which I have to use calculate the chi-squre test for it. For the explanatory variable Gender, and the outcome variable Vist. For gender I have Male, Female, and NotAnswered. The NotAnswered number is huge but I don't want it, if I use

pd.crosstab(df['Sex'], df['Visit'], margins=True)

I will have 3 rows and 2 columns, Is there anyway to omit the "NotAnswered" from the crosstab's result? I only want my crosstab table has two rows, Female and Male.

code to generate sample data

import pandas as pd
import numpy as np

sexes = np.concatenate([np.random.choice(["Male", "Female"], 90), ["NotAnswered"] * 10])
np.random.shuffle(sexes)

visits = np.random.randint(0, 2, 100)

# create the DataFrame
df = pd.DataFrame({
    "Sex": sexes,
    "Visit": visits
})