How to use the already-trained transformer model to make predictions using new data?

I trained a time series transformer/informer model using my own hourly data with a length of 6 weeks and successfully generated the model file. Now using this trained model, I want to make predictions using newer data, but not sure which function/method to use. Also the new data to feed to the model has only 1 week in length, are there any parameter to configure for the length of new input data? Thank you very much!