[4] Kowalczyk made his professional debut for the ŁKS first team on 26 February 2022, coming on as a substitute for Jakub Tosik in the 65th minute during a 1–1 away draw against GKS Jastrzębie in the second-tier I liga.
[11] On 17 July 2024, Kowalczyk returned to Poland to join newly promoted Ekstraklasa club GKS Katowice on a season-long loan, with an option to make the move permanent.
[13] In August 2022, he was called up to by Poland U-19's coach Marcin Brosz for training camp in Reda ahead of the 2023 UEFA European Under-19 Championship qualifiers against Bosnia and Herzegovina, Estonia and Italy.
[15] On 28 August 2023, Kowalczyk received his first call-up for the Poland U-20, and he subsequently gained his first cap for the team on 8 September during a 4–0 home win over Portugal in the Under 20 Elite League.
[18] Kowalczyk, a hard-working central midfielder, displayed remarkable maturity on the pitch early on, making his senior football debut at the young age of 14.