Can't insert to collection sample_mflix.comments

why can’t I insert data? the data is just copied from this source

I don’t know where the error is.
before this, I inserted data into so many collections I didn’t face any issues.

JSON format does not like linebreaks in the strings.

you possibly copy-pasted from a not-suitable-to-copy-code text and have:

{ ...
  "text":"Rem officiis ...
      dolor voluptatum ...
      nulla ...",
...}

you need to edit string linebreaks after copy-pasting.

{ ...
  "text":"Rem officiis ... dolor voluptatum ...  nulla ...",
...}

though just the blue-white coloring is not strong, you can still use that to differentiate strings in this context. you can see color change after “Porro” word where the error starts.