Julie here from Shopify Support.
It's great to hear that you're wanting to sell in multiple currencies. Are you using Shopify Payments? If so, aside from adding a currency selector to your theme, there are a few steps you'll need to take before you can enable selling in multiple currencies. You can view those steps and ensure that you've followed each one correctly here.
First, you will need to set up Shopify Payments to use multiple currencies. This can be done by heading to Settings > Payment providers. In the Shopify Payments section, you'll want to select Manage, then scroll down to the Multiple currencies section, where you can add any of our supported currencies. Here's what that looks like:
Once this is done, your customers can pay for their orders and receive refunds in their local currency, which can be selected automatically with the Geolocation app, or from a currency selector that's been added to your theme through one of these methods. With a currency selector, customers can select a currency of their choice; with the Geolocation app, the best language and currency will be recommended based on your customer's browser preferences and location.
To ensure that you have correctly enabled your store to sell in multiple currencies, it's important to review each step carefully. Once you've completed each step, it's strongly recommended that you test your multiple currency setup to ensure a smooth customer experience.
I hope this helps! If you need any further clarification, feel free to respond here directly and let me know.
With "currency selector", you need to be aware that this currency conversion is for visual purpose only. Upon checking out it is only the default currency that is available. Regarding geolocation tool, you are right, it will auto direct your visitors to correct URLs(like currencies) based on their locations. Geo Redirecting tool is worth checking out. It instantly redirects visitors to corresponding sites seamlessly based on their locations. Easy to set. No code is necessary. Shopify platform is perfectly supported.
Hope it helps!