Are you trying to , or download an existing document ? Are you using a computer or a phone ?
Go to the official conference website or portal (e.g., Scribd, academic databases, or the conference agenda page).
Use the "Share" or "Export" menu, select PDF as the file type, and save to your device.
If a PDF is embedded in a website and not obviously downloadable, try the steps in this YouTube guide to force a download. 2. Downloading "Stories" or E-books
If the file is too big to download or attach, use Adobe Acrobat online or similar tools to compress the file. To make this more useful, could you tell me: Is this a you are trying to download?
Once I know, I can give you the exact steps or link you to the right place.