Controlling Frame Rate deepstream-test3

I am using the reference application provided by deepstream, and I cannot find a way to fix frame rate. The video is running too fast. I have tried searching for documentation of ‘nvurisrcbin’ but to no avail, the element is mysteriously missing from documentation.
Is there a way to control frame rate when using matroska files in deepstream-test3?

Platform: AMD64
GPU: RTX 3080
OS: Ubuntu 20.04
DeepStream: 6.1.1