Currently topic suggestions can be created out of online files that
- The URLs must be secure (they must start with https://).
- The URLs must be publicly available, that is, they can't need a user to log in.
- For online files, we do not support file upload. You must provide the full URL to the location of the file, including the file extension, as in the example https://www.microsoft.com/thisisafile.pdf.
- For online files, we currently support PDF, DOCX, PPTX, TXT files and 2-column formats in TSV, XLSX (first sheet only), and CSV. The file extension must be included in the URL.
( from https://docs.microsoft.com/en-us/power-virtual-agents/advanced-create-topics-from-web )
Files being shared in OneDrive are not supported.
Please add support for files that are shared in OneDrive.