Modify the exchange rate of a currency

The two snippets below change the exchange rates of currencies.

This first snippet sets the exchange rate of the GB Pound to 2 GBP per USD.

add_filter( 'mycryptocheckout_api_account', function( $account )
{
 $account->data->physical_exchange_rates->rates->GBP = 2;
 return $account;
} );

This second snippet sets the exchange rate of BTC to 1 BTC per USD.

add_filter( 'mycryptocheckout_api_account', function( $account )
{
 $account->data->virtual_exchange_rates->rates->BTC = 1;
 return $account;
} );