First, split your file into chunks. Chunk size is up to you but must be 5 MB or less. If you attempt to upload a chunk larger than 5 MB you'll receive an error. The last number is the chunk number. This is used, to determine the order to reassemble the chunks on the server. So the second chunk would be POST /api/v2/files/{file_id}/versions/{v4_uuid}/chunk/2. The request body should be the binary data of the chunk. Make sure to set the Content-Length header.