7 But in the days when the seventh angel is about to sound his trumpet, the mystery of God will be accomplished, just as he announced to his servants the prophets.”

Read Revelation 10:7 Using Other Translations

But in the days of the voice of the seventh angel, when he shall begin to sound, the mystery of God should be finished, as he hath declared to his servants the prophets.
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.
When the seventh angel blows his trumpet, God’s mysterious plan will be fulfilled. It will happen just as he announced it to his servants the prophets.”