While adding your account, if you do not receive the activation code from Instagram, kindly try the steps below;
The verification code will be sent to your Instagram registered email or phone number by Instagram.
1. Ensure that your registered email and Phone number on Instagram are Correct.
2. Check your SPAM and SOCIAL tabs. Sometimes the verification code goes to the SPAM box or the SOCIAL Tab (for Gmail users).
3. Clear your browser cache and cookies and try again after 30 minutes. If you confirmed the above two steps and do not get the code. Kindly clear your browser cache and cookies then try again - See How to Clear Your Browser Cookies and Cache