@山下 大樹 Thanks for reaching out.
Currently Microsoft QnA supports only English language and other language as in roadmap to support in near further.
To answer your query - Currently you cannot use the event grid to get the event changes for your support request. The only supported in build resources are listed here. Further I don't see any Event Grid Partner Topics that can help you with your use case.
The workaround would be creating your own custom solution calling the Support ticket REST API for your requirement.
Please "Accept Answer" if the answer is helpful so that it can help others in the community.