Create customized mesh & modify it in runtime

Could you help me with some of my queries?? As I'm a beginner level Unity Developer, I want to create something like this..

https://www.linkedin.com/posts/jachimv_immersive-content-augmentedreality-ugcPost-6719947635261800448-WrN5

Queries:

1. What's the concept called?? The concept of scanning of marker line & creating a mesh in runtime.. If you help me with the name i can search on Google & try to create something like this..

2. How to change the roaster mesh up & down in runtime?? Just give me a proper name or something related to it.. will search it on google

3. Which AR platform should I use?? In Unity I have used Vuforia & ARCore.. which platform it is made?

Please it's a kind request help me out.. I will do RnD and try to create this type of experience..