Normally, I use axios with Typescript this way

const fetchTransactions = (PageNum: number, PageSize: number, Context_id: number): Promise<Transaction[]> =>
  axios
    .post<Transaction[]>(FETCH_TRANSACTIONS_URL, {PageNum, PageSize, Context_id})
    .then((response) => {
      if (response.status >= 200 && response.status < 300) {
        return response.data;
      }
      throw new Error(response.status.toString());
    })
    .catch(({ response }) => {
      throw new Error(response.status);
    });