Cannot compile .tflite to tpu tflite

[minhhoai1001]

I train tiny-yolov3 on darknet then convert to Keras model by follow instruction.
But when use edgetpu_compiler have error.

Edge TPU Compiler version 16.0.384591198
Started a compilation timeout timer of 180 seconds.
ERROR: Attempting to use a delegate that only supports static-sized tensors with a graph that has dynamic-sized tensors.
Compilation failed: Model failed in Tflite interpreter. Please ensure model can be loaded/run in Tflite interpreter.
Compilation child process completed within timeout period.
Compilation failed!

How to slove it.

OS: ubuntu 20.04
tensorflow: 2.6.0