Learn Swedish: Vi uppskattar insatsen för samhället. - We appreciate the effort for the society.

We use för because the effort is done for the benefit or in the interest of society. If we used till, it would sound like a physical object being handed to a recipient. If we used åt, it would imply society gave someone a specific chore to do on its behalf.

Does insatsen only mean effort?

Insats (here in its definite form, insatsen) is a very flexible word. In this sentence it means effort or contribution. However, it can also mean a financial stake (like a deposit for an apartment or a bet in a game) or an organized operation (like a police or military intervention).

Why does samhället end in -t instead of -en?

Samhälle (society) is an ett word that ends in a vowel. To make it definite (the society), you just add -t to get samhället. If it were an en word, it would get an -n or -en ending instead.

Can samhället also be translated as the community?

Yes! In Swedish, ett samhälle can refer to society as a whole, but it is also the standard word for a local community, a village, or a small town. You have to rely on context to know which scale is meant.