Reaching out before shopping with ~ておく


Grammar Explanation

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Since Cocoa will be making stew for dinner, Chino decides to communicate in advance to get ingredients other than carrots.

チノ:
「にんじん以外(いがい)(つた)えておこう

Here, おく is is modified to the volitional (showing intent to do) おこう. “I will send a message …”