How do I make use of getSimpleUploadUrl()

[danielmcfarland]

I've used the function getSimpleUploadUrl() to generate a URL to upload files to however I cannot seem to make use of it. Each time I try to upload a file I get the message 'SignatureDoesNotMatch', 'The request signature we calculated does not match the signature you provided. Check your key and signing method.'

How do I calculate the correct signature and attach it?