whiteboard sharing option

Hi, seeking advice on share option of whiteboard. I select a specific whiteboard aiming to share with users outsider my organisation. According to the guide, there should be a share option I can select after clicking on the ... on the right of the specific whiteboard record. I noticed I have only the Lock, rename, change owner, export PDF, export in new tab and move to trash options. Any advice to resolve this will be greatly appreciated.

thanks

AC