src/Model/Payment.php
public function setCurrencySymbol(string $currencySymbol): self
    {
        $conversions = [
            '€' => 'EUR',
            '$' => 'USD',
            '£' => 'GBP',
            '¥' => 'JPY'
        ];

        $currencySymbol = $conversions[$currencySymbol] ?? $currencySymbol;

        $this->currencySymbol = $currencySymbol;

        return $this;
    }
public function setCurrencySymbol(string $currencySymbol): self
    {
        $conversions = [
            '€' => 'EUR',
            '$' => 'USD',
            '£' => 'GBP',
            '¥' => 'JPY'
        ];

        $currencySymbol = $conversions[$currencySymbol] ?? $currencySymbol;

        $this->currencySymbol = $currencySymbol;

        return $this;
    }
@param string $currencySymbol

@return Payment