As pulykamell says most EFL teachers don’t speak the local language - at least initially. The only people I knew who spoke Estonian back then were “returnees” that’s to say Canadian or American Estonians whose parents had kept the langauge up at home.
If you have a qualification you know techniques which should mean you can teach English to speakers of any language. Again within the state education system things are different - you need a good degree of fluency in the local language in order to complete the paperwork, interact with colleagues and parents etc.