Immediately after John was called to "come up hither", he was in the spirit: "and, behold, a Throne was set in Heaven, and ONE sat on the Throne."
John's experience was similar to that of Paul, who was caught up into Paradise.
Whether in the body or out of the body they are uncertain,
The difference between them was that while Paul heard words that he was forbidden to speak; John was told to "write in a book" the things he saw and heard, and send them to the Seven Churches.