To get a single PDF file based on multiple reports in FastReport.Net, forming from the code of the user application. You need to load a single object and build several reports sequentially.
How to set a picture in a report from the user application code
It is not possible to set a picture in a report from user application code from .NET code. But this can be done in the FastReport.Net report generator. This article provides 3 ways to do this.