If you look at the progression of Seals to Trumpets to Bowls, you will note that the 7th Seal are the Trumpets and the 7th Trumpet are the Bowls.

There is no 7th seal event as there are for the first six ie the horsemen, then the martyrs then the Cosmic disturbances. Then we have the 6 Trumpet events the final being Revelation 9:13-21 but we don't see the 7th Trumpet till Revelation 11 with the announcement that the kingdoms of the world are now the Kingdoms of Christ - but there is no judgement as with the 6 trumpets preceding, and then from Revelation 15&16 come the Bowls judgements.

Before the Seals-Trumpets-Bowls progressions we see the Church in Chapters 2&3, then we read at Revelation 4:1 John is told to enter heaven and see what will happen after these things - after the church age. Chapters 4&5 deal with the elders - representatives of the first ingathering/harvest - before God's throne where the Lamb/Lion of Judah is revealed as the only one fit to open the scroll, which is sealed with 7 seals.

The scroll is the title deed to the earth - given to Adam in Genesis 1 when given dominion over the earth - in the fall this passes to Satan - Jesus says that satan in the ruler of the world. God is taking back his stolen possession.

The scroll is like a book open the seals to get to the Trumpets, the last Trumpet giving the Bowls.

Now inserted into the S-T-B narrative is additional information which is not part of the S-T-B narrative, and this is not necessarily in chronological order., e.g. Chapter 11 the Two Witnesses who take on the Beast from the Pit (Rev 11:5), who is allowed to kill them - but we don't see this Beast until Chapter 13.

Hope this helps.