What are the rules and requirements for such registration?
According to the legislation of Ukraine, branches and representative offices are separate subdivisions of legal entities (Article 95 of the Civil Code of Ukraine). That is, an individual entrepreneur cannot have a branch or representative office either in Ukraine or abroad.
A natural person - an entrepreneur can have several outlets (shops, kiosks, etc.) in different parts of the city or even in different cities or abroad. However, it is inappropriate to consider them branches. After all, a natural person, unlike a legal entity, cannot "separate" itself as a business entity.