How can I optimise GPT-J-6B for Heroku?

This is the code I found in the documentation:

from transformers import AutoModelForCausalLM, AutoTokenizer

model = AutoModelForCausalLM.from_pretrained("EleutherAI/gpt-j-6B")
tokenizer = AutoTokenizer.from_pretrained("EleutherAI/gpt-j-6B")

prompt = (
    "In a shocking finding, scientists discovered a herd of unicorns living in a remote, "
    "previously unexplored valley, in the Andes Mountains. Even more surprising to the "
    "researchers was the fact that the unicorns spoke perfect English."

input_ids = tokenizer(prompt, return_tensors="pt").input_ids

gen_tokens = model.generate(
gen_text = tokenizer.batch_decode(gen_tokens)[0]

If I add this to my code, the application crashes. How do I optimise this for Heroku?