How to implement currency update and purchase price storage?

Question

WordPress

Hello comrades.

I have a WP + Woocommerce site.

Please tell me how best to implement a regular (for example, once a day) price update relative to the exchange rate, i.e. there is a product, the client buys it not in rubles, but in euros, and we need to store this figure somewhere and display the price in rubles on the site.

And there are two global questions:
1) How and where is it better to store this amount (purchase price)
2) How to update it in relation to the course.