Hi there! For further reference, here is another solution worth checking out.
In your store, when the currency is changed, it adds a query parameter to the URL, like, exampleshop.com?cur=AUD, or exampleshop.com?cur=USD. There are tools can help you auto detect visitors among currency switches based on your visitors' locations, and redirect visitors to correct currency using URL parameter. For example, Geo Redirect. If a visitor is from Australia, and he goes to exampleshop.com, it will redirect and take him to exampleshop.com?cur=AUD, automatically showing Australia Dollar currency.