Here’s the interesting context around that seemingly simple link:
URL you shared ( soundcloud.com/activate ) returns a status. This typically means the page exists but is locked behind a login – you need to be signed into your SoundCloud account first before the server will show you the activation code entry screen. soundcloud.com/activate sign in
The 401 error means you tried to visit the page – SoundCloud’s server refuses to show the code-entry form until it knows who you are (so it knows which account to pair the device to). soundcloud.com/activate sign in