post https://api.hel.io/v1/charge/api-key
Creates a one-time pay link (charge) that can be used to collect a single payment from a customer.
NOTE: When using Helio on mainnet, set your Base URL to https://api.hel.io and generate your API keys from app.hel.io . For testnet, use https://api.dev.hel.io and generate your API keys from app.dev.hel.io.