Hi @bhavna 

This might be happening because Article field on KB Feedback task table does not refer directly to Kb_knowledge Table.

By default that field refers to another table named as "kb_feedback" and it is this table which refers to kb_knowledge table.

So, to achieve your requirement, you need to follow the steps below:

Update your record producer script as below:

var getNumber = producer.VariableName; //Replace "VariableName" with your Article Number Variable here

var createdFeedbackFirst = updateKBFeedback(getNumber);

if(createdFeedbackFirst){
current.article = createdFeedbackFirst; // This will update the Article field
}

function updateKBFeedback(getNumber){
var gr = new GlideRecord('kb_feedback');
gr.initialize();
gr.article = getNumber;
var succ = gr.insert();
if(succ){
return gr.sys_id;
}
}

Hope this helps. Please mark the answer as correct/helpful based on impact.

Regards,
Shloke