There a way to copy or backup boot.img from unrooted Android?

[Play Store]

I have seen other forums about backing up the boot.img from their unrooted Android phone, but is that true? I have a Ulefone U007 PRO which is unrooted and I wanted to root it using the boot.img. Is there any way in which I can back it up? For your information, I have no recovery partition and whenever I press VOL UOP/DOWN with power, it takes me to a Factory mode which allows me to test various things (but I cannot do that anymore because I mashed up both volume buttons (what stupid of me)), but there is no option for recovery. So, is there any way for me to back up the boot.img?
To clarify: Unrooted U007 PRO, no /recovery partition (so I cannot use any stock recovery as there isn't one OR custom recovery because the partition isn't there) and both the volume buttons, which take me to a Factory mode instead of Recovery mode, are mashed up.

 

[Rukbat]

You can try pulling the boot image using adb pull. That will get it on your PC. If Magisk works with it, it can restore the original boot image if you decide you don't want it to be rooted. (So many people want to root their phones, then find that they really don't need root.).

 

[Play Store]

What is the command?
adb pull ... boot.img \path\to\folder
Or what?