Using API PRO

Gnosis is a supported chain under Etherscan API PRO.

Therefore, all endpoints must use Etherscan's base URL and API key, and pass in chain ID `100` under the query parameter.

So instead of

https://api.gnosisscan.io/api?action=balance&apikey=YourGnosisscanKey

Use

https://api.etherscan.io/v2/api?chainid=100&action=balance&apikey=YourEtherscanKey