Button inside nested Gridspec

gistfile1.txt

import matplotlib.pyplot as plt
import matplotlib.gridspec as gridspec
from matplotlib.widgets import Button

def on_click(event):
    print("hey")

fig = plt.figure(constrained_layout=True)

gs = gridspec.GridSpec(2, 1, height_ratios=[14, 1], figure=fig)

gs1 = gs[0, 0].subgridspec(1, 1)
ax1 = fig.add_subplot(gs1[0, 0])
ax1.text(0.5, 0.5, "ax1", va="center", ha="center")

gs2 = gs[1, 0].subgridspec(1, 2)
ax2 = fig.add_subplot(gs2[0, 1])

b = Button(ax2, 'hey')
b.on_clicked(on_click)

plt.show()