Give it to Fodide
In Fodide, Settings → Connectors → Development → Apple: tap Pick the key file (.p8), type the Key ID and Issuer ID, tap Check, then Keep on this phone. Delete the downloaded file afterwards.
In Fodide, Settings → Connectors → Development → Apple: tap Pick the key file (.p8), type the Key ID and Issuer ID, tap Check, then Keep on this phone. Delete the downloaded file afterwards.