Send file using bot ms teams api

Question

Good afternoon. I need help sending the file from the bot to the client. I made an implementation on this tutorial [https://learn.microsoft.com/en-us/microsoftteams/platform/sbs-file-handling-in-bot?tabs=visualstudio
I receive a confirmation request to download the file, but the file is not downloaded

In the directory specified in contentUrl - empty - https://ispacepro-my.sharepoint.com/personal/*/Documents/Applications/FileUpload/file-sample_100kB.doc

At the same time, there is a file in the list of files in the application - but it is also empty

Can you help me?