To display a message (as shown in the image below) follow these steps. Bear in mind that if you want all your processes to behave in the same way, you will need to do this for all of them.
1. In Bizagi Studio, open the proyect and go to the Processes Module.
Select the process in the process tree view. Right click the process to open its Properties.
2. In the Properties window make sure you don't have a Global Form selected for the process.
3. Click Ok. Check your project in the Work Portal by completing an activity and having no further pendings in that case. The message should display.
To display a Global Form create one by following the instructions in this article: Global Form Article in Bizagi Help.
Select it in the properties window and click Ok.
After, Bizagi will show the Global Form defined instead of the message.