These are the effects described in Revelation 12:7-8.

In order to understand the events of Revelation, it is important to understand the chronology.
The events in the first five chapters are not yet visible to us humans.
The events are Chapter 1: Commission to John
Chapters 2 and 3: Judgment of the Church
Chapters 4 and 5: The Throne of God So, for us humans on earth, nothing is yet visible.

The events begin in chapter six with the opening of the seven seals. With the opening of the first four seals, the horsemen of the apocalypse emerge. The horsemen of the apocalypse are stopped by angels in chapter seven.

This is also not visible to us humans (see the topic: “The Horsemen of the Apocalypse”).

When the sixth seal is opened, something catastrophic happens to us humans. Chapter 6:12-13

12 When he opened the sixth seal, I looked, and behold, there was a great earthquake, and the sun became black as sackcloth, the full moon became like blood, 13 and the stars of the sky fell to the earth as the fig tree sheds its winter fruit when shaken by a gale.

Chapter 10 is very important for understanding the sequence of events in Revelation, because verse 7:5-7 states

5 And the angel whom I saw standing on the sea and on the land raised his right hand to heaven 6 and swore by him who lives forever and ever, who created heaven and what is in it, the earth and what is in it, and the sea and what is in it, that there would be no more delay, 7 but that in the days of the trumpet call to be sounded by the seventh angel, the mystery of God would be fulfilled, just as he announced to his servants the prophets.
52 in a moment, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, and the dead will be raised imperishable, and we shall be changed.

Chapters eleven and thirteen also agree, with forty-two months being viewed from different perspectives

Chapter 11:3: The courtyard of the temple will be trampled on for forty-two months
Chapter 13:5: The beast blasphemes God for forty-two months.

The conclusion of chapter eleven agrees with John's vision in chapter nineteen.

Chapter 11:16-17 The twenty-four elders fall down before God.
Chapter 19:4 The twenty-four elders fall down before God.

This clearly shows that chapters six to eleven and chapters twelve to nineteen are viewed in parallel from different perspectives.

These are the effects described in Revelation 12:7-8.

7 Now war arose in heaven, Michael and his angels fighting against the dragon. And the dragon and his angels fought back,8 but he was defeated, and there was no longer any place for them in heaven.
The seventh trumpet is sounded in Revelation chapter 11:15. Let's read it there.
The sounding of the seventh trumpet signals the end of the events of Revelation. The day of salvation is over. This corresponds with the words of the Apostle Paul in 1 Corinthians 15:52, where we read:
15 Then the seventh angel blew his trumpet, and there were loud voices in heaven, saying, “The kingdom of the world has become the kingdom of our Lord and of his Christ, and he shall reign forever and ever.” 

-----Chapter----------- Chapter----------- Chapter------------
---------6/12 -------------- 11/13 -----------------11/19------------

The Chronology of Revelation