Proof.
Since \(\mathrm{Mor}^{\mathrm{poly}, \mathrm{gr-proj}}(\mathrm{mod}_k^{\mathbb{Z}})\) is an object in \(\mathrm{Alg}_{\mathbb E_1} (\mathrm{Cat}[\mathrm{add}_{k}^{B\mathbb{Z}}])\), the statement immediately follows from the adjunction ([00CQ]). ◻