Add forecast to pivot table based on query

[chacham]

I created a query and a pivot table, and now want to add a forecast.

The query outputs the following columns: Company, Area, Department, Year, Month, Total.

The pivot table is based on it and has the following settings:
Columns: Year, Month
Rows: Company, Area, Department
Values: Sum of Total

The year and month make up the last year, so, right now, for example, it lists 2022/5-2023/4, with a total for each year and a grand total.



Now i want to add a forecast for the next 3 months on another tab. If i go to Data->Forecast->Forecast Sheet, the Create Forecast Worksheet popup has, "Use historical data to create a visual forecast worksheet" Then, "A forecast can't be created because the timeline isn't evenly spaced."

Is it a mistake to try to base the forecast on the pivot table?

 

[chacham]

Error was because of the total columns which can be removed under pivot table option and column options. I created date column in another tab with a formula, but then it said i had too much data. If i limited it to one row, it created the forecast, but that took up multiple rows, though i only had one per forecast. Instead, i used the average different over the last three months and just added it to the most recent total. That seems to work, for now.