Failed to load resource: the server responded with https://chain.so/api/v2/get_address_balance/BTCTEST/undefined a status of 404 () But when I'm put https://chain.so/api/v2/get_address_balance/BTCTEST/mikAVj3qeVAgQSHBTYHWywNGbe1tcmFMvn like manually it's working how can I solve it.