Best way to attach light to the bumper 2019 Yaris

[senioryaris]

Have 2019 yaris hatch LE as in the photo

Want to attach 2 lights (~200 g each, slim profile, 2 attachment points per light) to the upper flat lip of the bumper where arrows are pointing.

What is behind the bumper?
Is there a way to attach bolts from the top
and gaining access from the front to insert nuts from below (by drilling 4 perpendicular holes)

(2 of these holes will be covered by licence plate, two other can be masked by suitable covers)

Ideas are welcome!

Thanks, Adam