Javascript to retrieve related entity record using KeyValues not working

In CRM, I have written a JavaScript on Account entity form, to auto-populate related Primary Contact when Parent Account is selected however it is not populating any value in Primary Contact lookup and its without error. What is wrong in the script?

Also what are the possible ways to retrieve related entity value using Javascript ?

Hi partner,

If you want to set a value to lookup field, please use the following format.

// GET and SET Lookup / Customer field value
var functionName = function (executionContext) {

    // Access the field on the form
    var field = executionContext.getFormContext().getAttribute("parentaccountid");

    // Verify it does exist on the form
    if (field != null) {

        // Get its field value; Returns the Lookup object
        var value = field.getValue();

        // To get the Id, Name and Entity Name (account/contact)
        var reocord_id = field.getValue()[0].id;
        var record_name = field.getValue()[0].name;
        var record_entityName = field.getValue()[0].entityType;

        // Set its field value
        field.setValue([{
            id: reocord_id,
            name: record_name,
            entityType: record_entityName
        }]);
    }
}

BTW, if you want to get related entity value, you could use web api to do this.

1.Get the related record id from lookup field.

2.Get the related record data from web api. For example I want to get the full name of contact by contactid.

function GetRelatedData(executionContext) {
    var formContext = executionContext.getFormContext();

    //get if the contact allows to have a phone call.
    Xrm.WebApi.retrieveRecord("contact", "91af308b-a11b-ea11-a828-000d3a579c9f","?$select=fullname").then(
        function success(result) {
            var firstname=result["fullname"];
            

        },
        function error(error) {
            Xrm.Navigation.openAlertDialog({ text: error.message });
        }
    );


}