const options = {method: 'GET'};

fetch('https://api.coinbase.com/v1/tokenized-stocks/total-supply/{contract_address}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

123

{
  "code": 3,
  "message": "field 'contract_address' must be a 20-byte hex address"
}

{
  "code": 5,
  "message": "contract_address \"0x0000000000000000000000000000000000000001\" is not a supported tokenized equity token"
}

{
  "code": 123,
  "message": "<string>",
  "details": [
    {
      "@type": "<string>"
    }
  ]
}