Fund at task Level and Revenue at project level

Summary:

we are doing funding at top task level for billing purpose. But the revenue to be generated at Project level either using Amount based or Percent spent.

is it possible? whenever we create event with project it is asking task is mandatory.

Content (required):

without funding at project level is it possible to generate revenue at project level. we need project mandatory not only on contract.

Version (include the version you are using, if applicable):

23B

Code Snippet (add any code snippets that support your topic, if applicable):