A certificate of completion is not a state license.
A class at the Taller teaches lash application. A license is the state's, and it decides who may be paid to work on clients.
Licensing
What you receive, and what the state asks for
What you receive
A certificate of completion from Taller de Pestañas, with the class and the dates. It shows what you studied. It is not a license.
What the state asks for
In most states a license from the board of cosmetology or esthetics is needed to be paid for lash work. The hours of school and the exam belong to the board.
What to do first
Call your state board before you enroll anywhere. Ask what license lash extensions need in your state, how many hours of school it asks and whether a short class counts toward them.
Licensing questions
Do I need a license to enroll?
No. Anyone 18 or older can take a class. A license matters when you want to be paid to work on clients.
Can I work on clients after a class?
Only as your state allows. In most states that means a license first. Ask your state board.
Does a class prepare me for the state exam?
No. The Taller teaches lash application, not the board's exam. A cosmetology or esthetics school does that.
Where do I find my state board?
Search for your state's board of cosmetology. It lists the license types and the hours of school each one asks for.