How to modify the baseURL in axios depending on the current domain

What I'm trying to do is to create an Axios instance in my nuxt app and modify the baseURl to be the same as the domain but with some prefixes and import this instance from an external js file.

for example, I tried to interceptors the request and modify the domain but in the normal Axios package there is no referer to the current domain in '@nuxt/axios' module there is the referer of the current domain but only if I use the module:

axiosInstance.js:

import axios from 'axios';

// Note I don't want to use baseURL to be static.
const api = axios.craete();

api.interceptors.request.use( (config) => {
   const prefixedDomain = prefixDomian(config.headers.common.refere)
   config['baseURL'] = prefixedDomain
   return config;
}, (error)=> {
   return Promise.reject(error);
});

export default api

test.js:

import api from 'axiosService';

const settings = async () => {
   const setting = await api.get('/settings');
   return settings
}
export default settings

but this code doesn't work because the header is empty inside the config.

The only result that I want is to create an Axios instance with the baseURL prefixed and can import it and use it in an external file.