Autel MaxiIM KM100 is successfully able to add a 2023 Lexus LX570 smart key by OBD. I'm going to show the procedure below. Here, I have an original key and a spare key.

IMMO >> Lexus >> Manual selection >> USA >> LX570 >> 2016-2021 Smart Key >> Yes >> Control unit >> Keyless System(CAN) >> Number of smart keys
Turn on hazard warning lamps.
Number of keys: 3

Erase smart key.
Turn on hazard warning lamps.
Notice: This function clears all smart keys but the selected ones that have been retained.
Learned locations include: 3
All smart keys(except the selected ones that have already been retained) will be cleared. Press OK to continue.
Clearance is completed.
Now the number of keys: 1

Add smart key
Turn on hazard warning lamps.
Notice:
Each step must be completed within the specified time.
The positions for learning include: 6
Put a learned smart key close to the START button.
Put a smart key to be learned close to the START button.
Learning succeeded.
Now the number of keys: 2

Check the new key, it's working.
This is using Autel KM100 to program the 2023 Lexus LX570 key-adding successfully.

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