Need help with setting options of a custom field drop down list depending on Customer Request Type

[KartikA]

I am trying to set a Jira custom field drop down based on Customer Request Type and I have been struggling to find a solution from a lot of days. I did my research online and was not helpful either. I am pasting my code I used in Initialiser in behavior script but I am unsuccessful can you please let me know where I am going wrong with this request. It is working on the create page of service desk. I am trying to implement this when we try to edit a page

import com.atlassian.servicedesk.api.requesttype.RequestTypeService
import com.atlassian.servicedesk.api.requesttype.RequestType
import com.onresolve.scriptrunner.runner.customisers.PluginModule
import com.onresolve.scriptrunner.runner.customisers.WithPlugin
import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.issue.Issue
import com.atlassian.jira.component.ComponentAccessor
import com.atlassian.jira.issue.CustomFieldManager
import com.atlassian.jira.issue.fields.CustomField
import com.atlassian.jira.issue.ModifiedValue
import com.atlassian.jira.issue.util.DefaultIssueChangeHolder
import com.atlassian.jira.issue.util.IssueChangeHolder
import com.atlassian.jira.issue.MutableIssue;
import com.atlassian.jira.bc.issue.IssueService;
import com.atlassian.jira.bc.issue.IssueService.CreateValidationResult;
import com.atlassian.jira.bc.issue.IssueService.UpdateValidationResult
import com.atlassian.jira.issue.IssueInputParameters;
import com.atlassian.jira.issue.IssueInputParametersImpl;
import groovy.json.*;
import com.atlassian.jira.issue.Issue;





FormField requestTypeField = getFieldById ("customfield_10171")
def reqType = getFieldByName("Customer Request Type")


    Map fieldOptions = [:]

    
    if (reqType == "oti/96384970-60f4-44e7-aaf5-93f1dcdab5a3") { 
 
    fieldOptions.put ("", "None")
    fieldOptions.put ("28739", "New Field/Case Request")
    fieldOptions.put ("28740", "New GNO Request")
    fieldOptions.put ("28741", "New Process Flow Request")
        fieldOptions.put ("14690", "Other")


}
  

    requestTypeField.setFieldOptions(fieldOptions)