My torrent client is transmission. It has many ways to do what you ask.
First there’s a web ui which I can access from my pc or mobile. I can input the magnet link there and download.
Transmission also has an RPC client, and because of that many third party clients exist for it. Android apps, CLIs, etc. For all of which, i paste the magnet link and download.
EDIT: I believe Oracle cloud has something against P2P downloads, but I don’t remember what exactly.
For that use case, there’s two things you can do: