Looking for R help (Keras - Tensorflow)

I am in a voluntary research group at my University, I have been asked to help adapt some models made in R using Keras-tensorflow. I have limited experience with either. After 2 weeks I am stuck on a number of errors that I have been unable to resolve. Some errors arising from my inexperience working with tensors or atomic vectors. Others due to deprecation of some functions like fit_generator() from the work I inherited. This is neither directly course nor thesis related, though is tangentially related to my thesis work. I will give proper acknowledgement of your contribution with any submitted models. Sample error attached.