scaleinvariantgradient_cuda.cu - cannot compile

[KobiHaMitapes]

In this code private members of type "PersistentTensor" are defined. These do not exist in my TensorFlow in the OpKernel class.
Additionally and along the same line, a method allocate_persistent is used 4 times
OP_REQUIRES_OK(context, context->allocate_persistent(...
There is no allocate_persistent in the OpKernelContext class, in my TensorFlow.

Any ideas what to do? I am working on a Jetson Nano 2GB kit. Tensorflow version: 2.6.0. Cuda version 10.2.300. Could it be that my versions are too recent?

Thanks.