The distance from the center of the toilet outlet in my bathroom to the wall has been tiled is 38cm

This is the most difficult spacing number.

There are two main specifications of the toilet in the current market: one is 400 (note: the actual is 380).

The other is an eye relief of 300 (actually 280). There's also an eye relief of 350, which is just right for your size, but it's rare, which reduces your options.

In this way, if you choose an eye distance of 400, (the measured is 380), it is theoretically 10 different. But if your drain is 100 (which is usually the case), the outer diameter of the toilet drain is about 80 (the specification of the general domestic brand). This way there is a margin of 10, which means that if you are lucky, you can install it (but the flange on the side of the mouth should be the best).

But there are certain risks. (Because there is no margin at all).

If your sanitary space is not too small and there is no obstruction, choose a smaller one, and it is common for there to be a few centimeters of seams in the back.

This is a problem that should be considered when retrofitting hydropower and there may be an opportunity to adjust it.

This is a normal size, the general distance between the wall of the mouth is 35-42cm, you can install this standard size, and then see if you want to install the front drain or the back drainage.

You are asking how big the toilet is, this pit is quite suitable, the general toilet is fine, and if there is a problem, use a shifter to solve it.