For the handed doors there are several certified types of frame fixing systems:

1.Fixing with clamps and mortar.
2.Fixing with expansion screws.

When fixing with mortar the clamps have to be bent out. When fixing with expansion screws the not bent-out clamp will help as a distancer and the hole on it will be used for the expansion screw, suggested type length 12 cm. and diameter 10 mm. depending anyhow on type of wall.
In the section “SPECIAL DOORS” you can following more certified alternatives:

3.Fixing with embracing frame on plasterboard partitions.
4.Fixing with corner frame on plasterboard partitions.
5.Fixing with screws on sub-frame.
6.Fixing with flush frame in corridor.