Proper floor construction for terrace

Hello everyone,

I want to cover my terrace (approximately 2/3 covered) with 90x90x2 cm ceramic tiles (have it done).

Currently, there is a concrete slab with bitumen waterproofing membrane (as protection against rising moisture from below) and almost no slope.

Current condition:

The terrace has a maximum build-up height of about 15 cm including tiles up to the top edge of the sliding door. The length from the house wall to the garden is about 5 meters. (regarding slope)

The terrace is not enclosed, meaning the ends on two sides are "open" and should align flush with the garden.

How should the further construction proceed?

I have read that one can or should either:

- apply a sloped screed and then lay terrace tiles on it with drainage mat underneath

or

- pour drainage concrete wet-on-wet with the tiles. But then there is the problem that water may collect on the concrete slab if some water seeps through the tiles and drainage concrete?

What should be considered regarding frost protection?

How should the connection at the open ends to the garden be done?

Key points sealing, drainage, etc...?

Because if the ends are sealed, any possible water can no longer be drained?

Thank you all.

I am hoping for some expert feedback.