Publicly is correct

Ly is an old English word meaning “part of, like” When added as a suffix it changes an adjective into an adverb

Since public–public(ly)

There are many words that look similar to publically, but that is a coincidence of spelling Example

Cynical—–Cynical(ly) Trivial—-Trivial(ly) That’s

all there is to it and you will never misspell again! When you need an adjective to turn a noun into an adjective by suffix

LY LY TWELVE. I want just that idea: to change a noun into an adjective by suffix. Just remember when combining noun with adjective by suffix.