In this study, we developed an online competition system for RoboCup soccer simula- tion 2D. Due to coronavirus disease (COVID-19), the regular competition will not be held in 2020 as usual, so there was a need to develop an" online competition system "that enables the holding of non-face-to-face competitions. This system uses a chatbot system to automate match executions and team management. The chatbot API automates the execution of programs and tasks such as start server and start players. In this way, the system achieves competition completely online. This system was officially adopted for the RoboCup Japan Open 2020 soccer simulation 2D league competition in 2020, when the first official online competition was held. Thanks to this system, the competition management flow which had been carried out manually, has been automated. As a result, this system has made a significant contribution to reducing the burden of competition management.