Pre-Paid referral code, where to enter during the activation process?

Hi, so I have a Pre-Paid referral code ready and during a new activation of another pre-paid number/account on-line, I was very carful on each step but there is no prompt asking to enter the code all the way until the new account has been activated. So, what can I do now? Where exactly the step is to allow you to enter the referral code? I am using Brave browser maybe with pop-up blocked. Would that be the issue? I am trying the call-back support and the first call-back was a joke, she doesn’t understand a word I said and handed up on me and never call back  now I am trying a second time for the call-back help to see if they can fix the issue for me.  Any advice would be great as I need to create another account/number.