Adds or replaces the external identifier for an existing job. Include the string value of the new external identifier in the message body.
The Toast platform uses this external identifier as one of the 
unique, persistent identifiers for a job record. Changing the 
external identifier for an existing job might affect reporting 
and other Toast platform functions that select jobs using the 
externalId value.
The JSON string value of the externalId for the job 
record. Wrap the value in double quotation marks to make it 
valid JSON syntax.
Returns the updated job record.
"MyToastNamingAuthority:9876543210"{- "guid": "string",
- "entityType": "string",
- "externalId": "string",
- "createdDate": "2019-08-24T14:15:22Z",
- "modifiedDate": "2019-08-24T14:15:22Z",
- "deletedDate": "2019-08-24T14:15:22Z",
- "title": "string",
- "deleted": true,
- "wageFrequency": "HOURLY",
- "defaultWage": 0,
- "tipped": true,
- "code": "string",
- "excludeFromReporting": true
}