For many years, Odoo, an open-source add-on-based platform offering an extensive range of functionalities, including Enterprise Resource Planning, has constantly expanded its scope, resulting in an increased complexity of its software. To cope with this evolution, Odoo has developed an integration testing system called tour execution, which executes predefined testing scenarios (i.e., tours) on the web user interface to test the integration between the front, back, and data layers. This paper reports our effort and experience in extending the tour system with fuzzing. Inspired by action research, we followed an iterative approach to devise FuzzE, a plugin for Odoo’s tour system to create new tours. FuzzE was eventually developed in three iterations. Our results show that mutational fuzzing is the most effective approach when integrating with an existing testing infrastructure. We also reported one issue to the Odoo issue tracker. Finally, we present lessons learned from our endeavor, including the necessity to consider testability aspects earlier when developing web-based systems to help the fuzzing effort, and the difficulty faced when performing triage and root cause analysis on failing tours.