If you know what you are doing, I definitely recommend rooting it manually: if you need a framework, Magisk is probably a good choice, as they are most of the cases reversible, so if you would rather have your old, unrooted phone instead, you can unroot it without leaving any traces.
Don't use automatic rooting software, as, not only will you not learn how rooting works, you will give them a backdoor to access your phone.
Try and learn using TWRP and other open source software instead.
Edit: As you mentioned oxygen OS, is it a oneplus? If so, one of my phones is a oneplus, and I rooted it via TWRP and Magisk as well.
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