How do i use env variables in lifecycle files?

You need to import the env function in order to access it

const { env } = require("@strapi/utils");

module.exports = {
  beforeCreate(event) {
    const myEnv = env("MY_ENV_VAR");
    console.log("MY_ENV_VAR: ", myEnv);
    console.log("before create fired with data: ", event.params.data);
  },

};