I am 20 years old (I will be 21 in September). My vision defect is -13, -12. The defect has been there for about 3 years. Is such a large defect suitable for laser correction (if so, which type)?

It is possible to completely remove myopia down to -14 diopters. If the tests do not show any contraindications to the procedure, and the cornea is thick enough to correct that many diopters, you will be able to have laser vision correction. The type of procedure, i.e. its method, can only be determined on the basis of tests and a medical interview.