If you have set the default currency code in your WooCommerce settings but are displaying some products which use a different currency, here's how to replace the default currency symbol with the currency provided in the original data feed.

change-currency-symbol-to-match-products-currency-code.php

<?php

/**
 * Change the currency symbol for the WooCommerce product to match the currency
 * of the product supplied by the Datafeedr API.
 *
 * @see dfrapi_currency_code_to_sign()
 * @global WC_Product $product
 *
 * @param string $currency_symbol Current currency symbol.
 * @param string $currency Base WooCommerce currency code.
 *
 * @return string Updated currency symbol.
 */
add_filter( 'woocommerce_currency_symbol', 'mycode_change_currency_symbol', 10, 2 );
function mycode_change_currency_symbol( $currency_symbol, $currency ) {

	global $product;

	if ( ! is_object( $product ) || ! isset( $product ) ) {
		return $currency_symbol;
	}

	$fields = get_post_meta( $product->get_id(), '_dfrps_product', true );

	if ( empty( $fields ) ) {
		return $currency_symbol;
	}

	if ( ! isset( $fields['currency'] ) ) {
		return $currency_symbol;
	}

	$currency_symbol = dfrapi_currency_code_to_sign( $fields['currency'] );

	return $currency_symbol;
}