The Isan or Northeastern Thai language(ISO 639-3: tts), is a dialect of the Lao language.
Isan is a agricultural area and one of the poorest, least developed regions of Thailand, which contributes the perseverance of the Isan/Lao language in Thailang.
Wikipedia: Lao and Isan Language and comparison
There are few Isan learning videos on Youtube:
I search Lao learning videos instead.