A note on the twisted degree $6$ $L$-function for Hermitian cusp forms of degree $2$

Let $F$ be a cuspidal Hermitian eigenform of degree two over $\mathbb{Q}(i)$, with first Fourier-Jacobi coefficient not identically zero. Building on a paper by Das and Jha, we prove the meromorphic continuation to $\mathbb{C}$ and the functional equation of a degree six $L$-function attached to $F$ by Gritsenko, twisted by a Dirichlet character.