When you create an expense item in Setup and Operation, the two options give the same result. Both spread the amount evenly across the months in the period. The difference shows when parts of the budget have not yet been distributed.
How to do it
Go to Setup and Operation.
Open the expense item by clicking the name or the pencil on the row.
Open the Cost price estimate tab and click the icon to the right of the Remaining rev. Cost price estimate field. Choose a distribution. Distribute monthly cost price estimate evenly spreads the budget evenly across the months. Distribute remaining cost price estimate evenly only distributes the amount that has not yet been accrued. In your setup, "cost price estimate" may be called "budget" in the button names.
Adjust individual months if needed, and save.
Good to know
You can remove the amount in one month and place it in the next, for example if the site setup starts later than planned.
If the entire budget has not been distributed, the difference is shown as remaining budget. The forecast then deviates from the budget on the expense item.
Check that the budget on the expense item matches the estimate before you distribute.