If you go to 'My Center' and then select the option - 'My Friend', which has 3 options:
The first 2 options are the ways in which you can share access with a trusted person of your choice.
The first option- 'Scan QR Code to add' is an option through which you can scan a QR code and add a person and share the access to the lock with him or her.
The second option- 'Add Account' asks you the mail-id of the person with whom you want to share the access, and then if you select 'Send Request', a request will be sent to that person.
The person with whom you are sharing the access, has to go to 'My Friend' option and then he/she will have to select the option- 'Request List' wherein he will find the request sent to him by the admin.
Once he/she selects the option 'Agree', the admin has to 'Authorize' the person, and only then he/she will be able to see and access that particular lock to his/her system.
NOTE - The admin has to authorize the person to be able to give him/her the access to the lock.
You can easily 'Authorize' and 'Unauthorize' or revoke the access from a friend that you may have added in the past.