Hello @eUser123. It would be helpful to indicate the make and model of your device as that would make it easier to see what suggestions to make, or even better use the device codename and do a search for it on the forum here. That would also tell us if you have a phone with A/B partitioning.
Assuming this is the case I would advise following the Magisk Installation instructions that topjohnwu, its creator, maintains. You will see that you can’t use TWRP on this type of phone unless you have already created a modified boot image, because there is no longer a separate recovery partition. His instructions are detailed but quite clear and I have installed (and reinstalled after major version updates) Magisk in this way on my A/B device.
You will probably need a tool to extract the boot image from the eOS zip file as Magisk needs this on your device to create a patched image. Using Linux payload-dumper is the usual tool to “dump” all the image files from the zip file. I believe a version exists for Windows and Mac, but not having these systems I can’t help you there.