What guarantees does Ukraine provide for the preservation of funds acquired through my entrepreneurial activities?

According to subparagraph 40 of paragraph 14 of the resolution of the Board of the National Bank of Ukraine dated February 24, 2022, Kyiv No. 18 (as amended), Authorized Institutions are prohibited from conducting cross-border transfers of currency values from Ukraine/transferring funds to correspondent accounts of non-resident banks in hryvnias/foreign currency, opened in resident banks, including transfers made at the request of clients, except for cases of conducting operations to transfer funds in foreign currency by electronic residents (e-residents) to their accounts opened outside Ukraine, if such transfers are made at the expense of funds received from abroad from non-residents, after payment of taxes provided by Ukrainian legislation, and without using an electronic payment instrument.

Thus, at any time, you can withdraw your funds to your account abroad after the bank taxes your income, which will happen within 2 days.