[2] Onopriienko competed at the 2018 European Championships, winning team silver alongside Khrystyna Pohranychna and the Ukrainian senior group.[7][8] She competed at the 2019 European Championships in Baku, where she, Vlada Nikolchenko, and the junior group placed fifth in team competition.[2] In September, Onopriienko competed at Deriugina Grand Prix Final in Kyiv, where she won all-around gold ahead of Belarusian gymnasts Alina Harnasko and Anastasiia Salos.[23] Onopriienko and Khrystyna Pohranychna were selected as the individual rhythmic gymnasts representing Ukraine at the postponed 2020 Olympic Games in Tokyo.[26] After the Olympics, she competed at the Marbella Grand Prix Final, where she placed second all-around behind Russian gymnast Lala Kramarenko.[27] In the apparatus finals, she won the silver medal in ribbon, the bronze in hoop and clubs, and finished in seventh place in ball.They won a silver medal in the team competition together with the senior group (Yelyzaveta Azza, Diana Baieva, Daryna Duda, Yeva Meleshchuk, Anastasiya Voznyak, Mariia Vysochanska).She also qualified to the clubs final and won her first ever World Championship medal, a bronze behind Darja Varfolomeev and Boryana Kaleyn.Onopriienko started the competition season in February, at the Tartu Grand Prix, where she won the gold medal in the all-around in front of Elvira Krasnobaeva and teammate Taisiia Onofriichuk.At the Thiais Grand Prix, she was 5th place in the all-around and won two gold medals in the apparatus finals (hoop and ball).[42] The controversy surrounding the selection process sparked mixed reactions from fans, with some supporting Onopriienko and others justifying the choice of Onofriichuk due to her recent successes, including a bronze medal at the pre-Olympic European Championship.