In general, you can pay for an IWA membership with these options: UnionPay (UPOP redirect), American Express, JCB, Bank Transfer, Visa, MasterCard, Visa Debit, Mastercard Debit, AliPay, Visa Electron. There may be other additional option(s) depending on the country you are located in.
If you are experiencing any issues at any stage of the payment process, please contact members@iwahq.org