How to dynamically get a list of MultiPoint coordinates in GeoJSON format?

Question

Python

Good afternoon!
Recently, I came across the fact that when the algorithms for outputting coordinates are correct, instead of the correct list in the coordinates field, they display just an empty array:

{"type":"MultiPoint","coordinates":[]}

They must be rendered by loading them from separate columns in the Excel file in order for the dynamic Response in GeoJSON format to interact with the map services itself.

How to properly process and display coordinates?

Thank you in advance!

Problem code example