Automorphism group of a linear code

Let $C \leq 𝕂 𝑛 𝑞$ be a linear code. The automorphism group $A u t C$ is the group of all linear equivalences of $C$ with itself, code i.e. monomial transformations $𝜑 : 𝕂 𝑛 𝑞 \to 𝕂 𝑛 𝑞$ such that $𝜑 (C) = 𝜑 (C)$ ,