How do you add a service agreement to an asset?

[iwdinw2]

Hi,

I am trying to figure out how to add a service agreement to an asset.
Let's say I have an asset (Tape Library, Server, SAN, NAS,) with one year warranty and with an additional service agreement for three years I paid extra for.
And now I want to add this service agreement to the asset.
How is this done in snipe-it?

Do I have to add this to the tab "maintenances" within the asset?
What is the "Asset Maintenance Type" then?
Do I have to check the button "Warranty Improvement" in the "Asset Maintenance"?
And/Or do I have to add the Service Agreement Duration as the new warranty to asset?

please assist!

Cheers