What should be indicated in the payload

Hello,
What should be indicated in the payload of the code below?

import requests

API_URL = “https://api-inference.huggingface.co/models/sentence-transformers/all-mpnet-base-v2
headers = {“Authorization”: “Bearer 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”}

def query(payload):
response = requests.post(API_URL, headers=headers, json=payload)
return response.json()

output = query({
“inputs”: {
“source_sentence”: “That is a happy person”,
“sentences”: [
“That is a happy dog”,
“That is a very happy person”,
“Today is a sunny day”
]
},
})