Implement switching between currencies

Hello.
Could anyone please give me a tips about implementing currencies for customers?

I have a task to implement a switching between currencies in theme and in checkout page using Exchange Rate API as a source of currency rates.
The goal is to allow a customer to select any other currency and see this currency in theme and checkout page.

I implemented this feature in theme, but struggled with Checkout page.
Here is what I did:

  • send currency rates to cart attributes;
  • create Cart Transform Shopify Function;
  • extract exchange rates from Cart Attrivutes;
  • convert current prices to another currency using math operations;
  • update the price for Checkout Page;

But I can’t change a currency sign.

Maybe I should change my algorithm of currencies and use something else instead?
Thank you for attention.

From Partner Discussions to Shopify Functions

Added cart-transform and removed app-store, dev-stores, partner-dash