Trumpets 1-4 are judgments upon Babylon. The 5th Trumpet is the start of judgment of "Israel" and the start of 3 woes/ punishments.
God starts to punish, then relents and stops the punishment.
At the 6th Trumpet, 2nd woe, God starts to punish, then relents again and stops this punishment.
But at the start of the 2 witnesses 1260 days, God decides that he will not relent of this last punishment. God has 1 last 'test' whereby they have 1260 days and then comes the 7th Trumpet with the 7 plagues to finish the punishments.
Read Amos 7. 3 punishments, the first 2 God relents punishment.
Good commentaries here: https://www.bible-studys.org/Bible Books/Amos/Amos Chapter 7.html
https://www.biblestudytools.com/commentaries/matthew-henry-complete/amos/7.html