发现您需要修复代码中的几行，

let tokenUrl = 'https://login.microsoft.com/<tenantid>/oauth2/v2.0/token';
const getTokenRequest = {
   method: 'POST',
   url: tokenUrl,
   body: {
      mode: 'formdata',
      formdata: [{
            'key': 'client_id',
            'value': '<client_id>'
         },
         {
            'key': 'client_secret',
            'value': '<client_secret>'
         },
         {
            'key': 'scope',
            'value': '<api_scope>'
         },
         {
            'key': 'grant_type',
            'value': 'password'
         },
         {
            'key': 'username',
            'value': '<usr_name>'
         },
         {
            'key': 'password',
            'value': '<password>'
         }
      ]
   },
};
pm.sendRequest(getTokenRequest, (err, response) => {
   const jsonResponse = response.json();
   const newAccessToken = jsonResponse.access_token;
   pm.variables.set("GRAPHTOKEN-VAR", newAccessToken);  //Local Variable
   pm.environment.set("GRAPHTOKEN-ENV", newAccessToken); //Environment Variable
   pm.globals.set("GRAPHTOKEN-GLB", newAccessToken);  //Gloabal Variable
   if (err) {
      console.log(err)
   }
});

pm.sendRequest({
   url: "https://localhost/api/groups",
   method: 'POST',
   header: {
      'Content-Type': 'application/json',
      'Authorization': `Bearer ${pm.globals.get('GRAPHTOKEN-GLB')}`  // access the global variable
   },
   body: {    //also sending the JSON payload properly
      mode: 'raw',
      raw: JSON.stringify({
         "displayName": "MI-GroupInv-GRP-PERFweNf",
         "description": "MI-GroupInv-GRP-PERFweNf"
      })
   }
}, function (err, jsonResponseBody ) {
   const jsonResponse  = jsonResponseBody .json();
   const iD = jsonResponse.id;
   console.log("ID:",iD)
   if (err) {
      console.log(err)
   }
});