The Apostlesí Creed is not found in the Bible.
True, but the early Church recognized that it summarized the teachings of the Bible very well:
I believe in God, the Father Almighty, the Maker of heaven and earth, (Genesis 1)
and in Jesus Christ, His only Son, our Lord: (John 1)
Who was conceived by the Holy Ghost, born of the virgin Mary, (Luke 1)
suffered under Pontius Pilate, (Matthew 27:11-31)
was crucified, dead, and buried; (Matthew 27:32-61)
He descended into hell. (1 Peter 3:19)
The third day He arose again from the dead; (Matthew 28)
He ascended into heaven, (Acts 1)
and sitteth on the right hand of God the Father Almighty; (Acts 7:56)
from thence he shall come to judge the quick and the dead. (Matthew 25:31-46)
I believe in the Holy Ghost; (John 14:15-27)
the holy catholic church; (Matthew 16:18)
the communion of saints; (Eph. 2:19-22)
the forgiveness of sins; (Eph. 1:7)
the resurrection of the body; (1 Cor. 15)
and the life everlasting. (John 3:16)
The Apostlesí Creed was not written by the apostles.
It is unlikely that the 12 apostles wrote it, but it correctly summarizes their teaching and preachings, thus the appropriateness of the title.
Rather, it was written at least 150 years after the apostles had all died. so who was it that wrote the AC
We don't know who or when it was written, but I fail to see the importance of that information, as the creed itself has been accepted by the Church through the centuries as correctly summarizing the faith of the Church founded on the apostles.