^1:11saying, “Write ^[a]on a scroll what you see, and send it to the seven churches: to Ephesus, Smyrna, Pergamum, Thyatira, Sardis, Philadelphia, and Laodicea.”

saying,

"Write on a scroll what you see

The trumpet-like voice behind John tells him to "Write on a scroll (this revelation) of what he sees. He includes throughout what he hears; but it should not be mistaken that this is coming from John's imagination. It isn't. He actually saw it while in the Spirit.

At the end of Revelation, John testifies/verifies that he did as he was told - Revelation 22:18-19.

On a philosophic note: This book, "the revelation from Jesus Christ" concludes this record of the existence of mankind not unlike Moses' book, Genesis, is an explanation of the beginning of this existance. The Genesis has some interesting views as to how we, the present humanoid generation has come to be (Genesis 6). That being recorded, an unlimited God may have other humanoid-inhabited exoplanets with their own DNA-based story (open link in new tab). Their "literature" probably has its own "existance record", but this "revelation from Jesus Christ" only explains this present earth's physical and spiritual existance.

and send it to the seven churches: to

These churches really existed in John's day. They were/are located on the mainland to the northeast of the isle of Patmos. John apparently had ministered to each of them, perhaps in the order given here. It is interesting to note that the first three chapters of Revelation and verse 4:1 apply to the Church Age. Study each church in the following chapters for their shortcomings and successes. Do each of these typify a type of church today?

Ephesus,
Smyrna,
Pergamum,
Thyatira,
Sardis,
Philadelphia, and
Laodicea.

^[a] Or in a book