Pare de usar APIs fracas e lentas.
Comece a

const params = new URLSearchParams({
  apikey: process.env.SYSTEMZERO_KEY,
  url: 'https://vt.tiktok.com/ZSx2pMEgR/'
})

const res = await fetch(`https://zone.api.br/api/v2/tiktok?${params}`)
const data = await res.json()

console.log(data.download_url) // → mp4 sem marca d'água

import os, requests

res = requests.get(
    "https://zone.api.br/api/v2/tiktok",
    params={
        "apikey": os.getenv("SYSTEMZERO_KEY"),
        "url": "https://vt.tiktok.com/ZSx2pMEgR/"
    }
)

data = res.json()
print(data["download_url"])

curl "https://zone.api.br/api/v2/tiktok?apikey=$SYSTEMZERO_KEY&url=https%3A%2F%2Fvt.tiktok.com%2FZSx2pMEgR%2F"

// resposta real de GET /api/v2/tiktok
{
  "status": true,
  "owner": "Josué </>",
  "titulo": "#fyp #pobrezaextrema",
  "duracao": "18 second",
  "download_url": "https://zone.api.br/tmp/tiktok_1783860412419.mp4",
  "expira_em": "30 minutos",
  "stats": {
    "like": 19300,
    "views": 680800,
    "share": 10100,
    "comment": 126
  },
  "autor": {
    "username": "ivin262",
    "followers": 4766,
    "verified": false
  }
}