Quick answer — Konomi Suzuki and Ashnikko performed 1 anime theme, including "Recollect" from Re:ZERO -Starting Life in Another World- Season 4.
Konomi Suzuki and Ashnikko performed the anime theme songs "Recollect" (Re:ZERO -Starting Life in Another World- Season 4).
Konomi Suzuki and Ashnikko's first listed anime theme is "Recollect", the opening of Re:ZERO -Starting Life in Another World- Season 4.