Preliminary uploads a file to the cloud before sending it in a message, which can be useful for uploading of being recorded voice and video notes. In all other cases there is no need to preliminary upload a file. Updates updateFile will be used to notify about upload progress. The upload will not be completed until the file is sent in a message
| file |
File to upload |
| file_type |
File type; pass null if unknown |
| priority |
Priority of the upload (1-32). The higher the priority, the earlier the file will be uploaded. If the priorities of two files are equal, then the first one for which Client.preliminary_upload_file was called will be uploaded first |