As my TurboTax colleague VanessaIA responded to a similar question:
"A full-time student is a child who during some part of each of any 5
calendar months of the year was enrolled as a full-time student at a
school, or took a full-time on-farm training course given by a school or
a state, county, or local government agency. A school includes a
technical, trade, or mechanical school. It doesn't include an on-the-job
training course, correspondence school, or school offering courses only
through the Internet."https://taxmap.irs.gov/taxmap/pub17/p17-155.htm#TXMP172a931f
