Hi @ivanlukyanov,
Thanks for reaching out. Sure it is possible. We specialize in Bubble.io and you are able to accomplish it, but just take into consideration that you’ll have to pay for a monthly subscription in this case, because custom domain/subdomains are possible on a paid Bubble plan only, so you have to really decide whether it is worth it for low priority features. For more information on Bubble pricing, please visit Pricing | Bubble.
And for domain instructions, you can find more information here:
Hope it helps.
Best,
Alex