The Transpose function returns the transpose of the input mod m Matrix or Vector.

It uses the more flexible mod m Copy function to compute the transpose.

If A is a square Matrix, the transpose can be performed in-place.

This command is part of the LinearAlgebra[Modular] package, so it can be used in the form Transpose(..) only after executing the command with(LinearAlgebra[Modular]).  However, it can always be used in the form LinearAlgebra[Modular][Transpose](..).