Required qualifications for yoga instructor


hello community,

I am looking for information about required qualifications to become a Yoga instructor.

Is the term teacher and instructor used interchangable?

I found information about Yoga teacher and Yoga school but not for an Instructor. Which institutions are available to provide informations about recognized qualifications to obtain certification as Yoga instructor for Yin Yoga?

I found Yoga teacher for 30 hours recognized by Yoga Alliance. Yoga Alliance website they offer 200/500 hr certificate for teacher / schools but also mention that they are not necessarily recognized by governal institutes.

I am confused / unsure of which institutes are responsible for Yoga Instructors.

I am a nurse, have taken Yoga classes before (for myself) among other qualifications. and need certificate for Eurpe or Portugal.

I am looking for clarification on that matter, thank you.