Pass value in Axios without parameter name in a React Native app

Question

const getRating = () => {
  axios
    .post('https://example.com/api/engage.php', {
    "eyJnaWQiOiIxMjg5MTA3NjQifQ==",
    },{
headers:{
'Content-Type': 'application/json',
'api-token': 'Zk4gcwJFovIpPaXtgyA55l0BSi8ETAxfAntuq7zp1L-x4OP27G-9UtaChlNExufQ4msa38aHDNQdQQ',
}
}     
).then(function (response) {
      // handle success
      alert(JSON.stringify(response.data));
     
      
    }).catch(function (error) {
      // handle error
      alert(error.message);
    });
};

I want to pass encoded string value with the above API and the value doesn't have name. I have tried the same in Postman, and it's working. But how to achieve the same in React Native?