Using Management Api in post-login action and number of tokens per month limit

I want to update metadata in the organization when the user logs in for the first time.

It seems that the only way to do this is by importing auth0 npm package and then using Management API client to update the org.

Now as there is a limit on the number of tokens that I can get via client id and client secret per month, how can I cache the token for further use securely in the context of auth0 action?