run loadEnv passing any command which needs the env vars.
For example loadEnv sh install.sh
# .env
TEST="hola mundo"$ loadEnv env
# ...
# TEST="hola mundo"
# ...Install from deno.land/x and use it as loadEnv
deno install --allow-read --allow-env --allow-run --unstable -f -n loadEnv https://deno.land/x/load_env_files/main.ts