Creates a token with the given payment_details.

It is recommended to have a client application make this request directly so that sensitive payment information (e.g. credit card number) doesn't hit your server. Receiving credit card numbers requires your business to be PCI-DSS compliant. Once you turn your customer's details into a token, the token string can safely be sent to your server and used as payment_details to a future KOMOJU API request.

A currency may be optionally specified. When currency is provided, KOMOJU will ensure that the payment made using the new token is in the same currency.