The Spanish Ministry of Health has published an updated list of countries in the "green zone", which includes Ukraine. Therefore, Ukrainian citizens can travel to Spain without the need to provide vaccination certificates or negative test results for Covid-19, provided they fill out the sanitary control form in advance: https://www.spth.gob.es/.
For all passengers (including children) arriving in Spain by air or sea transport, including for the purpose of transit to other countries, there must be a pre-filled sanitary control form (on the portal of the Ministry of Health of Spain https://www.spth.gob.es/ or by downloading the Spain Travel Health mobile application -SpTH- on the phone) and received a QR code to be provided upon request by the representatives of the carrier company before boarding, as well as by the sanitary control services at the checkpoint at the port or airport upon arrival in Spain.
All passengers who intend to enter Spain are subject to sanitary control at the first point of entry, which provides at least a document check, visual inspection and non-contact temperature measurement.
For visa-free entry to Spain you need a valid biometric passport and get a health insurance policy for the entire period of stay in the country.
The list of countries or areas at risk, as well as the criteria for inclusion in it, are revised every seven days and are published on the website https://www.mscbs.gob.es/en/profesionales/saludPublica/ccayes/alertasActual/nCov/spth.htm