How to use pretrained pth to train MMYOLO with my dataset ?

[Tuerte]

I want to usr pretrained model to train my datasets. how to set config file.
I have set the dict(init_cfg="pretrained", checkpoint='pth_file'), but occured some issues, like this:
04/18 09:31:29 - mmengine - INFO - load model from: weights/yolov8_s_syncbn_fast_8xb16-500e_coco_20230117_180101-5aa5f0f1.pth
04/18 09:31:29 - mmengine - INFO - Loads checkpoint by local backend from path: /weights/yolov8_s_syncbn_fast_8xb16-500e_coco_20230117_180101-5aa5f0f1.pth
04/18 09:31:29 - mmengine - WARNING - The model and loaded state dict do not match exactly
unexpected key in source state_dict: xxxxxxxx
missing keys in source state_dict: xxxxxxx