Full Idea
Gödel's theorem does not refute formalism outright, because the committed formalist need not recognise the metalinguistic notion of truth to which the theorem appeals.
Gist of Idea
The formalist defence against Gödel is to reject his metalinguistic concept of truth
Source
Michael Potter (The Rise of Analytic Philosophy 1879-1930 [2020], 45 'Log')
Book Reference
Potter,Michael: 'The Rise of Anaytic Philosophy 1879-1930' [Routledge 2020], p.305
A Reaction
The theorem was prior to Tarski's account of truth. Potter says Gödel avoided explicit mention of truth because of this problem. In general Gödel showed that there are truths outside the formal system (which is all provable).