THIS HAPPENS AFTER THE SIXTH SEAL IS OPENED.
From biblegateway.com NIV
Revelation 7
After this I saw four angels standing at the four corners of the earth, holding back the four winds of the earth to prevent any wind from blowing on the land or on the sea or on any tree. 2 Then I saw another angel coming up from the east, having the seal of the living God. He called out in a loud voice to the four angels who had been given power to harm the land and the sea: 3 “Do not harm the land or the sea or the trees until we put a seal on the foreheads of the servants of our God.” 4 Then I heard the number of those who were sealed: 144,000 from all the tribes of Israel.

5 From the tribe of Judah 12,000 were sealed,

from the tribe of Reuben 12,000,

from the tribe of Gad 12,000,

6 from the tribe of Asher 12,000,

from the tribe of Naphtali 12,000,

from the tribe of Manasseh 12,000,

7 from the tribe of Simeon 12,000,

from the tribe of Levi 12,000,

from the tribe of Issachar 12,000,

8 from the tribe of Zebulun 12,000,

from the tribe of Joseph 12,000,

from the tribe of Benjamin 12,000.

The Great Multitude in White Robes
PLEASE READ ALL THAT IS HIGHLIGHTED.
9 After this I looked, and there before me was a great multitude that no one could count, from every nation, tribe, people and language, standing before the throne and before the Lamb. They were wearing white robes and were holding palm branches in their hands. 10 And they cried out in a loud voice:

“Salvation belongs to our God,
who sits on the throne,
and to the Lamb.”
11 All the angels were standing around the throne and around the elders and the four living creatures. They fell down on their faces before the throne and worshiped God, 12 saying:

“Amen!
Praise and glory
and wisdom and thanks and honor
and power and strength
be to our God for ever and ever.
Amen!”
13 Then one of the elders asked me, “These in white robes—who are they, and where did they come from?”

14 I answered, “Sir, you know.”

And he said, “These are they who have come out of the great tribulation; they have washed their robes and made them white in the blood of the Lamb.

WHAT DID HE SAY? " THESE ARE THEY WHO HAVE COME OUT OF THE GREAT TRIBULATION." THE RAPTURE IS IN THE MIDST OF THE TRIBULATION. THE SEVENTH SEAL IS NOT BROKEN YET. YOU DO NOT WANT TO BE HERE FOR THAT.