Use a Private Streaming Page to share unreleased music. You can leave it open, or lock it with a password.
Create the page
Tap New Page.
Choose Private Streaming Page.
Pick the album or project you uploaded.
Turn on a password
In the editor, open the Project tab.
Go to Access Control.
Turn on Password Protected and set the password.
Visitors will see This page is password protected.
If the page isn't asking for a password, check that Password Protected is on and a password is actually saved. Turning the toggle on with an empty field is not the same as locking it.
This only exists on Private Streaming Pages. A normal link in bio can't be password-gated.