Telegram Stars and Premium, straight from your code

import { FragmentAPIv3 } from "fragment-api";

const api = new FragmentAPIv3({
  mnemonic: process.env.TON_SEED,                 // signs here, never sent
  walletType: "v5r1",                             // or "v4r2"
  fragmentCookies: process.env.FRAGMENT_COOKIES,  // your Fragment account (KYC)
  trust: { maxTonPerOrder: 50 },                  // refuse to sign anything bigger
});

const result = await api.buy({ product: "stars", username: "durov", amount: 50 });
// no Fragment account? add  kyc: false

import os
from fragment_api_lib.v3 import FragmentAPIv3

api = FragmentAPIv3(
    mnemonic=os.environ["TON_SEED"],                  # signs here, never sent
    wallet_type="v5r1",                               # or "v4r2"
    fragment_cookies=os.environ["FRAGMENT_COOKIES"],  # your Fragment account (KYC)
    trust={"max_ton_per_order": 50},                  # refuse to sign anything bigger
)

result = api.buy("stars", "durov", 50)
# no Fragment account? add  kyc=False