Here’s a written transcript
https://www.nma.gov.au/explore/features/ned-kelly-jerilderie-letter/transcription
Sent from Mdewakanton Dakota lands / Sept. 29 1837
Treaty with the Sioux of September 29th, 1837
“We Will Talk of Nothing Else”: Dakota Interpretations of the Treaty of 1837
I found a YouTube link in your post. Here are links to the same video on alternative frontends that protect your privacy: