patch https://api.hel.io/v1/allowlist/add
Add a wallet address to your allowlist when restricting access to a paylink.
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.