Secondary y-axis is not plotting

Question

I created a bar plot and now I want to add a secondary y-axis as a line using 'Recovered' from my pivot table. Unfortunately, the data for secondary y-axis is not showing but the axis is displaying correctly.

Can someone help me with this? Thank you!

pivot['Unrecovered'] = pivot['Claim'] - pivot['Paid']
pivot['Recovered'] = (pivot['Paid'] / pivot['Claim'])*100
pivot

pivot output:

Fiscal Year	Claim	Paid	Unrecovered	Recovered
2018	788,602.37	610,283.05	178,319.32	77.39
2019	9,870,246.71	7,834,106.99	2,036,139.72	79.37
2020	7,661,541.11	5,839,581.89	1,821,959.22	76.22
2021	6,641,099.86	4,641,853.93	1,999,245.93	69.90
2022	3,124,225.48	700,148.52	2,424,076.96	22.41

# plot pivot table with secondary y-axis showing % Recovered

pivot.plot(y = ['Paid','Unrecovered'],
       kind='bar',
       rot=0,
       stacked = True,
       ylabel ='Amount ($)')
plt.ticklabel_format(style='plain', axis='y')
ax = pivot["Recovered"].plot(secondary_y = True, 
                         color = 'k',
                         marker = 'o')
ax.set_ylabel("Recovered")
ax.set_ylim(0,100)
plt.show()

Output : Recovered plot