Naxi (纳西语, also written Nakhi or Nasi) is a Tibeto-Burman language of the Naish subgroup, spoken by Naxi communities in and around Lijiang in Yunnan province, China, and across the Yunnan–Sichuan–Tibet border region. Its ISO 639-3 code is nxq. It is written today in Naxi pinyin, a romanisation used by the standard dictionaries; the older Dongba pictographic script belongs to ritual use and is not a general-purpose writing system.
Naxi is a Tibeto-Burman language of the Naish subgroup, spoken in the
Lijiang area of Yunnan, China. It is not related to Mandarin Chinese; the shared
vocabulary is largely borrowed. It has its own romanisation — Naxi pinyin —
whose letters do not have the Mandarin values an English reader would expect
(q and v, for instance, mark specific vowels and tones).
The heartland is Lijiang: Gucheng District, Yulong Naxi Autonomous County, and neighbouring counties such as Weixi, Yongsheng and Ninglang, extending toward the Sichuan and Tibetan borderlands. Related Naish varieties (Na/Mosuo around Lugu Lake, Laze in Muli) are close enough to be discussed together and distinct enough to need separate documentation.
Rather than take the description on trust, look at the material:
NaxiAI. “What is the Naxi language?” https://naxiai.com/naxi-language.