Hello and welcome to the Community!
I believe you're asking about the Confluence chart macro. Hopefully, this assumption is correct. With that said, once you've created your chart macro, you'll need to feed the macro "data" to populate the chart or bars in this case. You can do this by inserting a table within the chart macro, typically with 'Dates' on Column A and 'Values' in Column B.
Example images of this from our documentation:
Further information on this may be found at Insert the chart macro.
Hi @n.derosa ,
Here you may see hints with exact numbers while hovering your mouse above the graph line:
The Chart from Table macro also provides a wide range of graph types and supports dynamic Confluence macros (Jira Issues, Page Properties Report, etc.).