Salesforce : Concatenation issue in workflow

HI Team,
We need to retrieve the ID from the UserLogin table using the UserId from the User table in Salesforce.

  • Variable A: API to fetch the UserLogin ID
  • Variable B: Expression to extract the UserId from the User table within Salesforce

Please review and provide your inputs. Below is the code:
{
“name”: “URL”,
“description”: “Building dynamic URL to fetch userlogin.Id from userlogin table”,
“transforms”: [
{
“id”: “sp:transform:concatenate:string”,
“input”: {
“index”: 0,
“variableB.$”: “$.accountRequests[?(@.source.id==‘xyz’)].accountId”
}
},
{
“id”: “sp:transform:concatenate:string”,
“input”: {
“variableB”: “'”
}
}
],
“variableA”: “xxx.salesforce.com/services/data/v61.0/query/?q=select+ID+FROM+UserLogin+WHERE+UserId='"
}

getting below error:

Is the UserId from the User table in Salesforce a string or a number (like account id number or employee id number)?

Its a string. Not a number.

It seems that the part “index=0” is incorrectly placed in variableB.

Can you please guide what should the index then?

I’m getting the same error. Has anyone figured out a solution for this?

Define Variable defined:

{
  "name": "groupName",
  "description": "",
  "transforms": [
    {
      "id": "sp:transform:concatenate:string",
      "input": {
        "variableB": "_"
      }
    },
    {
      "id": "sp:transform:concatenate:string",
      "input": {
        "variableB.$": "$.identity.firstname"
      }
    }
  ],
  "variableA": "DL_Direct_Rpts "
}