How should I store access token from a 3rd part api

Hi i am using meteorjs and a 3rd party api to create users on 3rd party's database.

I am getting access tokens with oauth2 and tokens have 2 hour expiry. After getting the access token with an async function I use it with couple of different methods.

However instead of calling an async function every time I need an access token, I would like to store it on server until it expires.

what is the best practice to store them securely and use it globally on the server?

many thanks in advance

I end up using global var to store the token on server;

token = '';

Meteor.methods({
  refreshToken: function () {
    token = getToken();
  ...
});

and now

token

is available for all methods. and I also check if the token still valid and refresh the token if the expiry is within 300 seconds.And the code for that part is as follows:

    const EXPIRATION_WINDOW_IN_SECONDS = 300;
    const expirationTimeInSeconds = token.expires_at.getTime() / 1000;
    const expirationWindowStart = expirationTimeInSeconds - EXPIRATION_WINDOW_IN_SECONDS;
    const nowInSeconds = (new Date()).getTime() / 1000;
    const shouldRefresh = nowInSeconds >= expirationWindowStart;
       if (shouldRefresh) {
           try {
               //refresh the token
           } catch (error) {
               console.log('Error refreshing access token: ', error.message);
           }
       }