Logs file name should be like: callsign.adi
You can upload your entire WSJT/JTDX Log file.
The Log uploader tool will filter out the QSOs.
Usually, the file can be found in "C:\Users\\AppData\Local\WSJT-X (or JTDX)".
You can also open your FT8 software, go to File -> Open Log Directory and copy wsjtx_log.adi to your Desktop and upload from there.
You'll be asked for the callsign, locator and category after you upload your log.
Logs must be uploaded by the upload deadline.