Duplicity gives InvalidBackendURL error when setting up Backblaze B2

When running Duplicity with Backblaze's B2 as outlined in some articles : duplicity ~ b2://[keyID]:[application key]@[B2 bucket name] Real values hidden, but provided though the Backblaze B2 UI. I encounter the following error: InvalidBackendURL: Syntax error (port) in: b2://[keyID]:[application key]@[B2 bucket name] AFalse BNone [keyID]:[application key partial]\ Where the application key is partially chopped off at the slash. I have attempted many alternatives to escape the slash such as double quotes, single quotes, and backslash escaping, but nothing improves the situation.