Plotting joint probability of two random variable choices

If I have two variables, say

x = random.choices([0.25, 0.75], [25, 75])
y = random.choices([0.4, 0.6], [4, 6])

how can I plot a 2D chart of with x-axis between 0 and 1, and y-axis between 0 and 1, to show the multiplied probabilities of the two variables, in a heatmap style format?

Thank you