Project 1 - Hamming Code

In project 1, if there is a mistake in the message sent, is there an instruction to “fix” a parity bit if it’s wrong? or should I consider only fixing the original 4 - bit message ?

Alice sends to Bob a 7-bit string. This is the only thing which is transmitted. We don’t assign any special meaning to any of the bits. Your circuit needs to find and fix the error.

See also this answer.