Many stores offer incentives to sign up to their newsletters. This is really easy to do and will often lead to you being able to get a first time purchase coupon code. Check Huobi to see if they offer this. You will usually find a notification about it on the homepage.
If you are worried about spam, you could also try a temporary email service. Just go to Google and search for “Temporary Email”.
This can especially be useful around special occasions like Valentine’s Day (e.g. “LOVE”), Easter (e.g. “EASTER”), Halloween (e.g. “HALLOWEEN”), or Mother’s Day (e.g. MOM).
Other commonly used coupon codes include:
FALL, SPRING, FRIEND, WELCOME, WELCOME10, WELCOME20, FACEBOOK, INSTAGRAM, TWITTER, THANKS, SAVE, SAVE10, SAVE20, TEST