System.EmailException: SendEmail failed. First exception on row 0; first error: NO_MASS_MAIL_PERMISSION, Single email is not enabled for your organization or profile. Single email must be enabled for you to use this feature.: []
Error is in expression '{!sendEmail}' in component <apex:commandButton> in page selectcontactforcustomerfeedback: Class.sendEmail.sendEmail: line 28, column 1

here is the code

public with sharing  class sendEmail
{
    public Customer_Feedback__c cfc{get;set;}
    Customer_Feedback__c cusfb = new Customer_Feedback__c();
  
   
    public sendEmail(ApexPages.StandardController controller)
     {
        cfc = new Customer_Feedback__c();
     }
   
    public PageReference sendEmail()
    {
       cusfb.Contact__c = cfc.Contact__c;
       insert cusfb;
        system.debug('@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@'+cusfb);
   
 
    Contact c = [select Name,Email from Contact where Id=: cusfb.Contact__c];
   
    system.debug('@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@'+c);
   
            Messaging.SingleEmailMessage message = new Messaging.SingleEmailMessage();
            message.setSubject('A new External Case Comment has been posted');
            message.setPlainTextBody(cusfb.Id);
            message.setToAddresses(new String[] { c.Email });

            Messaging.sendEmail(new Messaging.Email[] {message});
 
 
   ApexPages.Message myMsg = new ApexPages.Message(ApexPages.Severity.info,'Registered Sucessfully, Feedback Security Code is sent to the Contact Email.');
   ApexPages.addMessage(myMsg);
    return null;
   }
}