In February 2021 it was announced that Fluxá would be making his debut in the Formula Regional European Championship with Van Amersfoort Racing, partnering F4 UAE title rival Francesco Pizzi and Mari Boya.

[14] However, following a late coming-together with teammate Gabriel Bortoleto in Race 2,[15] the Spaniard would have to wait for two rounds until scoring his next points, a pair of eighth-place finishes at Le Castellet.

He finished his season with another fifth place, this time at Mugello, which meant that Fluxá ended up twelfth in the standings, behind his teammates Hadrien David and Bortoleto.

[18] At the beginning of 2023, Fluxá took part in the Formula Regional Middle East Championship with Mumbai Falcons, garnering three podiums and finishing fourth in the drivers' standings.

[19] The Spaniard opted to remain in FRECA for a third successive season in 2023, switching to Prema Racing to partner Andrea Kimi Antonelli and Rafael Câmara.

In late September 2022, Fluxá partook in the FIA Formula 3 post-season test with Van Amersfoort Racing during the second and third days.