Can I share my private key (12 secret phrases) from my wallet? For example, with my leader?
Not! If your leader asks you to do this, then most likely he is a scammer. In no case should you share your private keys with anyone.
The phrase is generated when you create a wallet once and forever, it can not be reset or changed. This is the only way to restore access to your wallet anywhere and anytime. Write it down on a piece of paper and keep it in a secure place.
If the phrase ends up in the hands of strangers, it could result in the loss of your funds. If you lose the phrase, your wallet will be impossible to restore.
You can read more in this article > List of common mistakes that may lead to a loss of your funds