Does OptiStruct support user-defined element like Abaqus UEL

Hello forum users,

I am curious about this question: user-defined element in OptiStruct?

Does OptiStruct support this kind of user subroutine like Abaqus UEL?

What I want to do is to define a special element's stiffness matrix for static analysis and I have the version in Fortran for Abaqus UEL.

No idea and resources can be found online about OptiStruct user-defined element?

Any answer is helpful and much appreciated.

Thank you!