Where's Whatsapp identity (private) key located?

According to the end-end-end encrypted messaging protocol named Signal Protocol and implemented also in Whatsapp, each user has a long-term identity key pair, in addition to some one-time ephemeral keys and a signed prekey. The identity key, namely the one mentioned in the official [documentation](https://scontent-fco2-1.xx.fbcdn.net/v/t39.8562-6/309473131_1302549333851760_6207638168445881915_n.pdf?_nc_cat=107&ccb=1-7&_nc_sid=ad8a9d&_nc_ohc=5LgX9LwZXrQAX_jxK6A&_nc_ht=scontent-fco2-1.xx&oh=00_AT-ufvZCX0Iqf6hLRS6QjklA2JfDtUUaMa0szXYhD6eEBw&oe=63467C9D) in page 4, is used in the first triple Diffie-Hellman agreement and signs all the prekeys. Does anybody know where this key pair is saved? I'm assuming here a full access to the memory of the device. In the axolotl.db file I can find traces of current ratcheting keys but not of the identity key.