Hi,
There´s nothing wrong with this Amazon text.
But generally I don´t recommend to learn from "advertising sites". They are often wrong, incomplete or at least rather "selling" focussed.
Instead I recommend to use semiconductor manufacturers, universities or professional sites.
I did not think about two inductors in series or parallel. Indeed the LCR meter will always see the resulting inductance and can not differ between the two inductors.
Usually
* "series mode" with LRC measurement means: L (C) and R in series.
* "parallel mode" with LRC measurement means: L (C) and R in parallel.
The meter just sees the voltage, current and the phase shift. And it needs the user information (ser/par) to calculate the correct L and R values.
(Because they differ in series and parallel mode)
Klaus