Good day. The rod is clamped/spread into the door frame and therefore does not need screws.
How well it holds then depends on how much it is clamped by twisting it apart, whether this is done horizontally and at right angles to the frame and what the material and surface of the frame look like.
Always test carefully first, pad the floor if necessary and refrain from doing exercises with swing, head-over-heels etc. I use fixed mountings for these.
For these I use fixed bars or rings.
Bars attached to the top of the frame and supported from the side (not screwed) are suitable for a little more exercise, but I would not recommend exercises with momentum here either.