Link’s various abilities in Zelda: Tears of the Kingdom allow him to create new objects and vehicles. However, given the massive creative freedom, remembering and repeating all these steps every time you want to create a vehicle can be tiresome. That is where the Autobuild ability in Zelda: TotK comes in.
As the name suggests, Autobuild automatically builds constructs for you, as long as the required resources are nearby. The ability basically acts as a recipe book in Tears of the Kingdom. Stuff you have created in the past gets stored in the history of Autobuild. You can then use this Autobuild history to recreate things at will in Zelda: TotK.
How to unlock Autobuild Ability in Zelda: TotK
Autobuild ability in Zelda: TotK is optional, unlike the core abilities, and can only be unlocked by doing a couple of side quests. It all starts with talking to Josha and Robbie at the Lookout Landing and running their errands in the depths.

To get this ability, start by talking to Purah once you descend from the Great Sky Island. As you help her collect the data from the Lookout Landing Skyview Tower, she will reward you with a Paraglider in Tears of the Kingdom, and you can begin your Hyrule journey.
Once you have the Paraglider, before leaving for anywhere else, go to the basement of Lookout Landing, where you will find Josha and Robbie. Speak to Robbie, and you’ll get your first quest, “Camera Work in the Depths.”
Once you have the quest, now is the time for you to head towards the Depths. Collect some Brightbloom seeds and arrows, and then go into the Depths. You can choose any way you feel comfortable, but we will enter the area by jumping into the Forest of Time Chasm in Zelda: TotK. You’ll find the area pretty dark initially; thus, use the Brightbloom seeds you collected to make it bright.
The area is full of enemies, and these enemies can cause you irreversible damage; therefore, try to avoid any combat with them. Your aim here is to reach Lightroom, and once you get there, you will find a statue. Take a picture of it and return to Lookout Landing.
Start A Mystery in the Depths Side Quest
As you return, Josha will give you another quest in Zelda: Tears of the Kingdom, “A Mystery in the Depths.” To complete this quest, you must return to the Depths, where you took a snap of a Statue. Follow the path the statue is pointing toward, and you’ll reach another statue.

Similarly, keep illuminating the tracks using Brightbloom seeds, and eventually, you’ll reach Great Abandoned Central Mine. You can reach this mine by traveling south from the point of descent.

Once you reach the Great Abandoned Central Mine, talk to the Steward and Engineer there to get the Autobuild ability. They will ask you to build two constructs, one with Ultrahand and one with the Autobuild ability. As soon as you do that, Master Kohga will appear to challenge you in a battle.
Master Kohga Boss Battle

The battle begins with Master Kohga revolving around you in a vehicle and charging attacks in Zelda: TotK. Therefore, all you need to do is make the best use of arrows. Point the arrows towards the rear end of his car; as the arrow hits it, he will be stunned. You can then run towards the car and unleash an attack with your most potent weapon.
However, the stun will only be for some time; as soon as you see it ending, run far and make the same arrow attacks. Repeating this multiple times will defeat Master Kohga in Tears of the Kingdom. After defeating Master Kohga, go to the Construct inside the mine. And you will finally get the Autobuild ability unlocked.
How to use Autobuild in Zelda: TotK
Once you have unlocked the Autobuild ability, you can construct your vehicles anywhere in Zelda: TotK. Hold L, and select the ability from the wheel drop-down menu to do so.
As you do it, you will see many vehicles. Unfortunately, you can’t keep your favorite vehicles at the top, so you must go through the entire list each time you use this ability.