Hey ​@Melina Braverman , thank you for reaching out to the Figma Forum!

• In order to share your file only with the people you want to give access, one workaround is to disable link sharing by selecting ‘Only invited people’  (so that only team members and anyone you invite to the file or project can access the file.)

Here are the steps from our guide:

Disable link sharing to prevent anyone from accessing the file without explicit or inherited permissions.

1. Click the Share button in the toolbar.
2. Click the audience setting.
3. Select Only invited people to disable link sharing. Only team members and anyone you invite to the file or project can access the file.
4. Click the ✕ to close the share modal and return to the file.
    

• Also, if someone has lost access because they only had it through the file link (i.e., they were never invited to the team, project, or file), and you want to grant them access again to the file, you’ll need to manually re-invite them. 
  => To do this, go to the Share menu and enter the email addresses of those you wish to share the file with, then set their access level (either Can view or Can edit). You can follow the steps outlined in our guide: Adjust or Remove access.
   

• Keep in mind, the URL itself will not change or be disabled. However, individuals who only had the link will no longer be able to view the file. They will encounter an access error when trying to open it.
   
• As a more "drastic" alternative, you could duplicate the existing file, make sure that link sharing on the duplicate is disabled, then delete the original file. This way, the new file will have a completely new URL that will not be accessible to those who only have the old link.

Hope this helps!