ᐅ Screed installed with slope – drying time before waterproofing?

Hello everyone,
we have a part of the basement that extends beyond the exterior wall of the house and is located at the entrance area.
That means if you drill through the ceiling of this small space (3m wide (10 feet), 1m deep (3 feet)), you end up in the garden walkway.

Anyway, water leaked through the ceiling here because the waterproofing was damaged and there was no slope.
Therefore, I removed the natural stone tiles, cleaned the masonry and the ceiling, and created a slope using concrete screed (C25, 0-8mm aggregate) with a thickness of 4cm (1.6 inches) at the thickest point—4° inclination.

I wanted to ask how long I should wait before applying the bitumen waterproofing membrane by torching it on?
The natural stone tiles will then be reinstalled on top of the membrane.

I know that for interior areas, the screed should cure for at least 28 days before covering.
But the bag (Sakret concrete screed) mentioned a drying time of only 3 days.
That confuses me.
So I wanted to ask for some advice.

Best regards,
Mattes

Until today