bad voltage regulator?

2017 SR5
53K miles
would not start yesterday
replaced Duralast Gold battery bought 06/2019
battery tested out with bad cell
Oreilly tested after new battery showed 13.2 - 14.4V range and then read
(voltage regulator failure) message
Worker recommended driving to work today and come back to retest, maybe computer resets or something.
voltage gauge needle is at or right below 14V while driving
have not noticed any flickering of lights, cluster panel lights on, or anything prior to seemingly a dead batter that needed a jump yesterday.
anyone have thoughts or suggestions (pending retesting the voltage)
I understand the voltage regulator is housed inside the alternator, so replace the whole alternator if regulator is bad?
TIA