Trainig model accuracy

my model stuck in training accuracy at 91%
what should I do to increase it

You are not supposed to post code solution here!

What kind of accuracy do you need to achieve? Accuracy can vary depending on implementation, data, complexity of task, and many other factors.

Some guidelines can be:

You could try changing model size and or architecture.
You could use dropout or other regularization like skipped connections.
A different optimizer, training iterations.
Changing hyper-paramenters.
Data augmentations, you can use tensorflow data augmentation functions. etc etc.

This is a trial and error process!