Either the church has authority to make declarations regarding both the canon of Scripture and regarding doctrine. One cannot exist without the other for the declaration of the canon of Scripture is in itself a question of doctrine. Now if this authority existed in the past it must continue to exist today.
It never did exist for the Catholic Church. They just deluded a lot of people into thinking it did. God entrusted His word to the Jews NOT the Catholics. The Catholic Church adding the apocrypha did not make them scripture.
Now: Either the church has authority to make declarations regarding both the canon of Scripture and regarding doctrine. One cannot exist without the other for the declaration of the canon of Scripture is in itself a question of doctrine. Now if this authority existed in the past it must continue to exist today.
"Authority" wasn't the word you argued for in your last post. You talked about whether the church (then or now) was "competent" to judge doctrine and canon. That's an entirely different topic. Authority might be conferred by the laying on of hands, but it's a much different argument to talk about how competency is passed on.
The church did not declare the canon of Scripture, but they confessed what was from the apostles. Similarly, the church does not declare doctrine, they can only confess what was already revealed.
One cannot exist without the other for the declaration of the canon of Scripture is in itself a question of doctrine.
The belief that apostles had authority to declare doctrine, and the judgement of what was authentic from the apostles, does not equal the authority of the apostles.
Now if this authority existed in the past it must continue to exist today.
If I recognize the authority of the apostles, that does not mean I have the authority of apostles. Recognizing the authority of the apostles is doctrine. Collating their authenticated works is not doctrine.