Using Approval Activity in the workflow we can create dynamic approval task for the approver to whomever we selected as Approver in the Catalog form
1.

2. Consider the above variable name is "u_manager"
3. Bring the Approval activity into the Workflow and Check ( Mark it True ) the Advanced option
4. Paste the below code in the "Additional Approvers Script"
var answer = [];
answer.push(current.variables.u_manager);
1.
2. Consider the above variable name is "u_manager"
3. Bring the Approval activity into the Workflow and Check ( Mark it True ) the Advanced option
4. Paste the below code in the "Additional Approvers Script"
var answer = [];
answer.push(current.variables.u_manager);