Read very carefully section 5.2.3 from Dumas et al. book. It outlines how workshop-based discovery can work. Then, watch the following video that will refresh your memory of business process analysis and will add some details, so you get an idea of how to proceed with designing/modeling/documenting a business process.

Normally, you would do the workshop with post-its, markers, flipchart papers, whiteboards, and other equipment. However, in difficult times, we need to find some workaround. Therefore, we will use some of the available online whiteboard tools. You can use one of the tools listed here. And to give you the inspiration to structure your workshop, you can look here for MIRO tips.

However, brainstorming or creative thinking techniques that use post-its and whiteboards are not exactly the same as process modeling. Therefore, go through some of the following links to inspect, how post-its and whiteboards could be used in the business process analysis context.

• How to use Sticky Notes to Diagram A Process
  
• General modeling tips visualized by stick-it notes
• Post-it guide from the manufacturer

Here, you can watch an example and explanation of why it is useful to use post-it notes to process modeling.

And if in the future you will do a workshop with post-its "offline", watch this video in advance, it could save you some troubles :-)