Summarizing is a normal study habit, and using a tool to speed it up is fine as long as you don't pass the output off as your own original thinking; it can be considered an appropriate way to speed up the summarizing process. It is inappropriate for a student to directly copy an AI-generated summary into their essay, report, or article, without first rewriting the summary in their own words and citing the original source of the summary.
The summary you create using the tool should be used as a note or reference, not as a final draft of your writing. If you would like additional clarification regarding the differences between appropriate summarization and plagiarizing when summarizing, please review this guide that outlines how to summarize without plagiarizing; you may also wish to run your completed work through the Quetext checker, to ensure that you have not committed any acts of plagiarism, before submitting it.