[5] He was later promoted to the reserves in Segunda División B ahead of the 2018–19 season,[6] and made his senior debut on 6 October 2018 by starting in a 1–1 home draw against CD Atlético Baleares.

[7] On 30 October 2018, Peña was called up to the main squad for the first leg of round of 32 tie with Cultural Leonesa in the Copa del Rey as a backup to Jasper Cillessen,[8] being an unused substitute in the 1–0 away win.

[17] Peña returned to Barcelona as his loan deal expired, and made his official first team debut under manager Xavi in a 4–2 away win over Viktoria Plzeň in the UEFA Champions League on 1 November 2022.

His sole under-21 appearance was on 12 November 2020 against the Faroe Islands in Marbella, coming on at half time for Álvaro Fernández in a 2–0 win in qualification for the following year's European Championship.

[22] Due to the isolation of some national team players following the positive COVID-19 test of Sergio Busquets, Spain's under-21 squad were called up for the international friendly against Lithuania on 8 June 2021.