He finished fourth at the
Czech Athletics Championships over
800 metres in July 2019 in
Brno, running 1:51.39. He won the Uhřice Circle - Run around Uhřice whilst competing for the University of Brno in January 2020. He won the
Czech Indoor Athletics Championships title over
1500 metres in 2022, and over 800 metres in 2023. He competed for his country at the
2023 European Cross Country Championships in
Brussels, Belgium. He set a new personal best in the 800 metres at the Czech Team Championships in
Hodonín in September 2023, with a time of 1:47.15. He lowered it to 1:46.57 in winning the Czech indoor title in 2024. He won the Czech Indoor Academic titles over 800 metres and 1500 metres in January 2025 in Ostrava. He made his international major championships debut at the
2025 European Athletics Indoor Championships in
Apeldoorn, Netherlands, finishing fifth in his preliminary heat, although was later disqualified following collision with another athlete. He was selected for the
2025 World Athletics Indoor Championships in
Nanjing, China, in March 2025, where he finished fourth in his heat in a time of 1:49.76 and did not progress to the next stage. Kotyza won the 800 metres at the 2026 Czech Indoor Athletics Championships in Ostrava.{{Cite web | url= https://worldathletics.org/competition/calendar-results/results/7235769?eventId=10229556&gender=M |date=1 March 2026 |title=Czech Indoor Championships ==Personal life==