You can look up the CUDA compute for the RTX 2080 Ti on the NVIDIA website:
Which says that you need a CUDA compute capability of 7.5
The RTX 2080 Ti is a Turing-based card.
The CUDA toolkit documentation, CUDA Toolkit Documentation has the details of when 7.5 capability was introduced. The details about the compabiliity for your card are at Turing Compatibility Guide :: CUDA Toolkit Documentation you.
There you will find that you need CUDA 10.0 or higher if you want to recompile your program to have native support for your RTX 2080 Ti.