How can a newly created “unit” with a 3% rate become a VAT payer?

Newly created businesses can voluntarily register as VAT payers during the state registration of a legal entity or individual entrepreneur.
If individuals transition from a simplified tax system to paying other taxes and fees, they must meet certain requirements and submit a registration application.
If individuals do not have taxable operations or their operations are below 1,000,000 UAH (excluding VAT), they must submit a registration application within a specified timeframe.
Registration applications for voluntary VAT registration must be submitted electronically, following the requirements of Ukrainian laws on electronic documents and electronic trust services.
Newly created businesses can declare their intention to voluntarily register as taxpayers during the state registration process, and the relevant application or information is transmitted to the controlling authorities according to the law on state registration of legal entities and individual entrepreneurs.

Note that this post was (partially) written with the help of AI. It is always useful to review the original source material, and where needed to obtain (local) advice from a specialist.