RTK Query - Changing the default header from fetchBaseQuery not working

[bylly1]

For almost all endopoints I need the headers.set("Content-Type", "application/json") but there are also some endpoints such as those for uploading files where I need to replace Content-Type", "application/json with Content-Type': 'multipart/form-data. From what I read in other topics, the content-type is set automatically from FormData, but in my case is not working. I also tried to set it manually but still not working

// api.ts
const baseQuery = fetchBaseQuery({
    baseUrl: '/',
    headers: { 'Content-Type': 'application/json'},
    prepareHeaders: (headers, { getState, endpoint }) => {
        // i set this as default for all endpoints
        headers.set("Content-Type", "application/json");

        const token = (getState() as RootState).auth.access;
        if (token && endpoint !== 'refresh') {
            headers.set('Authorization', `Token ${token}`);
        }
        return headers;
    }
});

const baseQueryWithReauth: BaseQueryFn<string | FetchArgs, unknown, FetchBaseQueryError> = async (
    args,
    api,
    extraOptions
) => {
    let result = await baseQuery(args, api, extraOptions);
 
    ...rest of the code from reauth
    return result
}
const api = createApi({
    baseQuery: baseQueryWithReauth,
    endpoints: () => ({}),
});

// exampleApi.ts
export const pageApi = api.injectEndpoints({
       endpoints: (builder) => ({
         uploadMediaPage: builder.mutation<
            Partial<ExampleProps>,
            { _id?: string; file: File; type: string;  }
         >({
            query: ({ _id, ...formData }) => {
                let bodyFormData = new FormData();
                bodyFormData.append('file', formData.file);
                bodyFormData.append('type', formData.type);

                return {
                    url: `http://localhost:5000/${_id}/upload/`,
                    method: 'POST',
                    body: bodyFormData,

                    // I tried to set manually but is not overwriting the one from api.ts
                    headers: {
                         'Content-Type': 'multipart/form-data',
                    },
                };
            },
        })
})