Shopify single customer lifetime value and currency conversion

[KuznetsEnvy]

Shopify docs say that liquid variable {{  customer.total_spent }} contains the total amount that the customer has spent on all orders in the currency's subunit – and that the value is output in the customer's local (presentment) currency.

The store in question is on a plan called "Shopify" (does not have Shopify Plus).

I'm trying to send an analytics event containing this value from Shopify standard order status page via additional scripts. For the analytics to work correctly I need to either send customer's local currency – or have {{ customer.total_spent }} converted to my Shopify's store currency (in my case Euro).
1. How do I get customer's local currency ISO code?

2. Is it possible (and how) to convert {{ customer.total_spent }} to store currency using the conversion rate that is currently set up for a given Shopify store?