Need help or template for creating an S curves given a gantt chart and contract costs

As the title says I need help creating an S curve. Basically the only data I have is costs of contracts and a gnatt chart. Sorry not sure how to tackle this or really explain it all that well or if its even possible given the materials. So lets say I have a contract for $100 framing for the project, the gantt shows the overall framing then the subsections that go into framing work. However, the contract only has the framing and not the breakdown. I was thinking I could convert the gnatt into some sort of numerical that would determine the curve of the payments from the contract over time. If anyone has tips or a template of something similar that would be a big help!

If I can't somehow convert the gantt into a curve of work done I would settle for making a generalization something like this tool does:
(I can't post a link because I am new, but google procore forecasting tool Apply Advanced Forecasting Curves)

If someone has a template where I can insert a line item and choose whether its a front-end, bell-curve, back-end, linear curve that could also work. Thank you!

Here's part of the gantt (I would manually convert this to excel if I could do this). Yes it would be easier if I had a breakdown of payments, but I don't just the overall contract. So for example in the uploaded image I have the contract amount for Sitework and Foundations, but not the individual jobs under them. My instructions were not very clear, so I'm trying to merge this data into a visual graph the best way I can. I think the best way to do it is use the gantt to determine the curve for a costs over time line. So for example where work overlaps it would be highest and as the work comes to a close it'll go down to 0, in like a bell curve fashion.

Attachment 838216

Try this attachment. I have the Gantt just not in excel form. Converting it would be easy, but time consuming which is why I haven't committed to converting it yet. I feel like the most important part of the Gantt is the start and end date, so what I want to do is basically link the cost to a time period for multiple line items then convert that to a graph showing costs throughout project lifecycle

Gantt Example.png