How to get this boundary condition?

$$\int_{\partial \Omega}(-v\nabla \Delta u\cdot\mathbf{n}+\alpha\nabla^{T}vH_{u} \mathbf{n})ds=0$$, for all $$v$$ which satisfies$$\nabla v\cdot n =0$$ on $$\partial \Omega$$, derive the boundary condition:$$\nabla \Delta u\cdot\mathbf{n}+\alpha \nabla(\mathbf{t}^{T}H_{u}\mathbf{n})\cdot \mathbf{t}=0$$ on $$\partial \Omega$$. $$\mathbf{n}$$ is unit normal and $$\mathbf{t}$$ is unit tangent vector along the boundary.

I have no idea how to get this boundary condition.