From your article:
"It has a magnitude of just 20, according to NASA's Jet Propulsion Laboratory
NEO Earth Close Approaches database. For reference, that's even dimmer than the dwarf planet Pluto. The faintest naked-eye stars are around
magnitude 6, and a typical six-inch telescope can see stars of around magnitude 13 or 14. "
There is confusion here between magnitude and absolute magnitude.
It has an
absolute magnitude (H) of 20. This object recently reached 14th magnitude, had it had a closer approach it would have become even brighter. In 2130 it will have a closer approach where it will become brighter than 13th magnitude...