curl -X POST \
  -u "<client_id>:<client_secret>" \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "grant_type=client_credentials&scope=clients:write" \
  https://api.fitsociety.io/public/v1/oauth/token

const options = {
  method: 'POST',
  headers: {
    Authorization: 'Basic <encoded-value>',
    'Content-Type': 'application/x-www-form-urlencoded'
  },
  body: new URLSearchParams({grant_type: 'client_credentials'})
};

fetch('https://api.fitsociety.io/public/v1/oauth/token', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://api.fitsociety.io/public/v1/oauth/token"

payload = { "grant_type": "client_credentials" }
headers = {
    "Authorization": "Basic <encoded-value>",
    "Content-Type": "application/x-www-form-urlencoded"
}

response = requests.post(url, data=payload, headers=headers)

print(response.text)

{
  "access_token": "fspt_0123456789abcdef0123456789abcdef0123456789abcdef",
  "token_type": "Bearer",
  "expires_in": 3600,
  "scope": "clients:write"
}