Hi @Vikash Pandey,
Welcome to the LastPass Community.
I understand that you are adding people to your organization but they are not receiving the activation code email. Normally this issue could be related to multiple scenarios. One of the most common scenarios is that the users already exists in LastPass meaning that they already have an account with the email you are inviting. The other reason could be that they have a type of block/bounce on their email or that the email is being block by the email provider.
I recommend you to create a case with our support team to provide them with the emails associated with your account, to locate the reason of the issue. For security we can not review emails in the community since is public. To create a case or callback request access to this link https://support.lastpass.com/s/contact-us?language=en_USlog in, you will see the option to create a call me request or create a case and one of our agents will contact you as soon as possible.
Kind Regards,
Alejandra
LastPass Tech Support