Using summarization models for paraphrasing

I’m using summarization models for short sentences. I found that summarization models do not change the sentences much (many times, they are kept intact) for short sentences. I saw some models on model-hub which are finetuned for performing paraphrasing. I did not see any information on how it was done. Can you please share how to finetune summarization models for better paraphrasing of short sequences (<128) ?