eSMS Links gives you two ways to control access to a link.
Expiry
Set an Expires date when creating a link. After that date the link stops resolving and shows an "expired" page — useful for time-limited offers or event links. You can also pause a link at any time from its detail page, and re-activate it later.
Password protection
Add a password to a link and visitors must enter it before they're redirected. This is handy for sharing gated content or internal resources. Password protection is available on Business plans and above.
Passwords are stored securely (hashed) and never shown again — keep a copy where you share the link.