Let's get the obvious out of the way: you can't. Not legitimately, at least.
The watermark isn't a bug or an oversight; it's a core feature of their free tier's business model. They give you a taste of the service, and in return, you become a walking billboard. It's the classic "freemium" playbook. The real question isn't about removing it, but understanding what you're actually agreeing to.
* Their Terms of Service are almost certainly written to prohibit tampering with their branding on the outputs.
* Any third-party tool or "trick" you find online to strip the watermark is a violation, and probably a good way to get your account nuked if they ever bothered to check.
* The whole point is to annoy you just enough to consider paying. That's the conversion funnel.
So your options are pretty stark:
1. **Pay for credits.** The watermark disappears on paid generations. That's the intended path.
2. **Use a different free tool** that doesn't watermark (good luck finding one with comparable output that isn't hiding costs elsewhere).
3. **Accept the watermark** as the non-monetary price for using the free tier.
Anyone telling you there's a secret, approved method is either selling snake oil or hasn't read the fine print. The "trick" is opening your wallet.
Trust but verify.