The Langlands reciprocity for affine Hecke algebras establishes an equivalence between two geometric constructions: one is the convolution algebra of Iwahori-bi-invariant complex-valued functions on $G(\mathbb{Q}_p)$, and the other is the convolution algebra defined on the equivariant K-theory of the Steinberg variety of the Langlands dual $G^L(\mathbb{C})$ , developed by Kazhdan–Lusztig and Ginzburg. These constructions were further applied by Lusztig and by Ginzburg–Vasserot to the geometric realization of affine quantum $\mathfrak{gl}_n$. For affine iquantum groups of type AIII, which are closely related to geometries of types BCD, the first construction has been given by Fan, Lai, Li, Luo, and Wang. Meanwhile, Su and Wang provided the K-theoretic construction for a class of type AIII affine iquantum groups. In this talk, we address the remaining class of type AIII affine iquantum groups not covered by Su and Wang, and also present an alternative approach to the case already treated by Su and Wang that avoids the use of localization. This is joint work with Changjian Su and Zheming Xu.