Hello! @LastPass User
Welcome to the LastPass Community.
We truly apologize for the problem with the share item, looking into your account details, this behavior is due to your account type, the user who share this item with you must likely is using a business account and yours is a personal free account, free or personal accounts does not have access to this tool, we truly apologize for the problem.
The only possible work around will be upgrading your subscription to LastPass Business.
Please let me know if you need additional help.
Greetings!
Verlaine | Customer Care