Spouse visa - ILR sponsor - IHS cost query

[Suj0303]

Hi, I am on ILR which expires in 2024.
I am applying visa for my missus next month and want to know what date do I need to fill in the IHS visa expiry.
Do I submit my visa expiry date - which then covers 5 years IHS
Or
Do I submit visa expiry date 3 years from the application costing us £1200

Thanks in advance.

[seagul]

visa expiry date 3 years