Starting off with an analogy where is the Earth’s centre?
In 3-D space the answer is simple, assuming the Earth is spherical in shape (which technically it isn’t), its geometrical centre is a point in its interior where the distance of this point to any point on the surface is a constant value defined as the radius.
Instead, if the question asked where is the centre on the Earth’s surface which is an example of 2-D space with a spherical symmetry, the answer is any point on the surface can be arbitrarily the centre even though there is no true geometrical centre.
The observable universe is modelled as part of a surface extended into 3-D space with a time dimension (space-time) of a much larger entire universe which could be infinitely large as the observable universe is essentially flat based on curvature measurements using the cosmic radiation background.
Like the Earth’s surface the observable universe has no true geometrical centre and any point can be arbitrarily chosen as the centre.
The situation is made even more ambiguous as space-time is expanding where the recession velocity of distant galaxies is proportional to the distance from the observer according to Hubble's law.
The observer in this case can be anywhere, they will find the recession velocities follow the same pattern hence the laws of physics, in this case Hubble's law, is the same whether the observer is on Earth or any other location in the universe.