What specific steps are required? When COULD it have been enacted?

https://en.m.wikipedia.org/wiki/Insurrection_Act_of_1807

The poster above addressed some of these points. It may have also been enacted here: https://en.m.wikipedia.org/wiki/Donald_Trump_photo_op_at_St._John%27s_Church

Despite the article stressing that it was only discussed, read the following:

6:23 p.m.: Park Police make the first of three announcements directing protesters to leave. The announcement[a] is largely unintelligible even to protesters at the front of the crowd.[75] Two additional announcements were made at 6:26 p.m. and 6:28 p.m.[18]

Dig into this more.

What specific steps are required? When COULD it have been enacted?

https://en.m.wikipedia.org/wiki/Insurrection_Act_of_1807

The poster above addressed some of these points. It may have also been enacted here: https://en.m.wikipedia.org/wiki/Donald_Trump_photo_op_at_St._John%27s_Church

Where specifically does it say it has to be publicly enacted? What specific steps are required? When COULD it have been enacted?