To ADD or DELETE code for smart lock,  you need to:

Download the APP

 Know the lock PROGRAMMING CODE

Schlage Encode Plus Smart WIFI, WB499.  Add OR Delete code

6ba1nam5tam

 ADD Code

 DELETE Code

Schlage BE375 Electronic Keyless

4chin1tam4ba

Schlage BE365 electronic keypad. 

Add OR Delete Code

Up to 19 codes

Igloo Keybox3

Add or Delete Code in the APP,

 Igloo Home

Default code 12345678.  Must change after programming

Orange Lion

Default code 12345678. Change after programming

Add code, press 2

Delete code, press 3

1-time code, press 7

TEEHO Default code 123456. Change after programming

Lockin Smart Lockbox

Video Add OR Delete code

Video