Could not parse example input, value: When sending request to BERT model

I have downloaded tf.SavedModel, and by using tf Serving I am serving it as REST API.
But whenever I make a request to predict the endpoint I get this error.

Could not parse example input, value: .... [[{{node ParseExample/ParseExampleV2}}]]

CURL Example:

curl --location --request POST 'http://3.124.206.151:8501/v1/models/tf_saved_models:predict' \
--header 'Content-Type: application/json' \
--data-raw '{
    "inputs":"hello"
}'

Here is the feature mapping json file.

{
   "version": 1,
   "features": [
      {
         "label": "data",
         "feature_id": "a153faf1-849e-4f95-a677-1a8be5bc7e09",
         "encoding": "text"
      },
      {
         "label": "label",
         "feature_id": "e03a77b2-4cdd-4c6b-ba60-3c5baaebaca8",
         "encoding": "categorical"
      }
   ]
}

Am I missing something here or do I need to preprocess the text before sending it?