Update a Connection

Set authentication information associated with a merchant's account on the tax provider's infrastructure: - [HTTP Basic Authentication](https://developer.mozilla.org/en-US/docs/Web/HTTP/Authentication) (developer.mozilla.org) credentials - (optional) Tax provider profile used in customized endpoint urls for tax provider calls. This is only available for tax providers that support this feature. The configured `username`, `password`, and `profile` (if available) is used to authenticate each AP...