1 Peter 3:15: "But in your hearts revere Christ as Lord. Always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have. But do this with gentleness and respect."
The Greek word that is translated to "answer" is "apologia".
[apología (from 575 /apó, "from" and 3056 /lógos, "intelligent reasoning") – properly, a well-reasoned reply; a thought-out response to adequately address the issue(s) that is raised. [An "apology" in classical times had nothing to do with saying, "I'm sorry," but rather was a reasoned argument (defense) that presented evidence (supplied compelling proof)]
To give a reason for a conclusion is to provide some claim that is not identical with the conclusion, that supports the conclusion. For example, if someone asks me why I believe the Cubs are going to win the world series again, I would not be giving a reason if I said "The Cubs are going to win the world series again because the Cubs are going to win the world series again". That's not a reason for the conclusion, that's just a repeating of the conclusion. A reason would be "The Cubs are going to win the world series again because they have the same stellar core players with some key additions that strengthen them even further". That may not be a very detailed or good reason, but it is a claim that is not identical with the conclusion, so it's a reason.
Notice that 1 Peter 3:15 does not say "Always be prepared to presuppose Christianity when anyone asks you why you believe in Christianity". People like Sye Ten Bruggencate constantly say things like "You already know the Christian God exists". That is a blatant violation of 1 Peter 3:15. That verse doesn't say "Always be prepared to just assert that everyone already knows Christianity is true when people ask you why you believe Christianity is true". That is not an apologia.