@秀也 渡邊 Thanks for your reply. I'm glad to see you were able to resolve your issue. Thanks for posting your solution so that others experiencing the same thing can easily reference this. Since the Microsoft Q&A community has a policy that the question author cannot accept their own answer, they can only accept answers by others, I'll repost your solution in case you'd like to Accept the answer.
Issue:
You are having trouble with speech-to-text functionality in the Japanese version of "speech studio". You are unable to drag and drop an audio file with a red mark. Additionally, you are requesting information on how to download and install the English version of "speech studio".
Resolution:
You were clicking in different places. There was no error message. You were able to solve this problem.
On a side note:
You were not able to attach the jpg pic in Q&A platform and you were getting error Unauthorized request.Please make sure you are using the correct credential.
I have shared this feedback with the Q&A platform team. For now, you can try logging off and re-login into the Microsoft Q&A forum and then try reload the page and then try attaching the image.
If this plan doesn't help, please let me know. I will share the other alternatives, for you to send me the jpg screenshot.