Rough 'Em Up + What step of the round is "before the end of the round" triggered in?

[Shosuro006]

Coxatris — Today at 3:55 PM Rough 'Em Up says, "Before the end of your round..." What step is "before the end of the round" triggered in?

Dragonhatter — Today at 4:05 PM
After threat is resolved

Answered in Discord: https://discord.com/channels/643518732999589892/991158333039972373/1036007929830199378