import seaborn as sns
import scipy.stats as stats
import matplotlib.pyplot as plt

plt.rcParams["figure.figsize"] = [7.50, 3.50]
plt.rcParams["figure.autolayout"] = True

x = [2.0, 7.5, 9.0, 8.5]
ax = sns.distplot(x, fit_kws={"color": "red"}, kde=False, fit=stats.gamma, hist=None, label="label 1")
l1 = ax.lines[0]

x1 = l1.get_xydata()[:, 0]
y1 = l1.get_xydata()[:, 1]

ax.fill_between(x1, y1, color="red", alpha=0.3)
ax.margins(x=0, y=0)

plt.show()