Click the + at the end of the tab bar and select Fund Settings

1. Select the Fund that will be added to opportunities by default if no Fund is selected either directly on the opportunity or through the Campaign
2. Check if you want to apply validation rule to make sure that the amount of the opportunity is same as allocations
3. You can select Record Types that won't have automatic allocations
4. Check this box if you want to make sure that only received Payments are marked as posted, and check if you would like to make sure allocations are not edited on posted opportunities
5. Users selected here will be able to reverse opportunities and edit records after they are posted. This is typically handled in cooperation with your Accounting department.
6. Click Save to confirm. Even if you've made no changes, click Save anyway to make sure the correct settings are established.

You will see this message once settings are properly configured.