Windows XP is 32 bit and not supported on the 3020.

You will NEVER be able to get XP booting on this model.

The last version of this series that had XP support was Class 1 BIOS 3010

https://www.amazon.com/Dell-Optiplex-3010-Desktop-Computer/dp/B00AKSJB8E

https://www.dell.com/support/home/en-us/drivers/DriversDetails?driverId=G54YD

https://dl.dell.com/FOLDER02061319M/1/3010-xp-A05-G54YD.CAB

You cannot point to a cab file however you must extract the contents via 7zip.

https://www.7-zip.org/download.html

The earlier models like the 360 380 390 also work with XP.

XP drivers and BOOTING are NOT forthcoming EVER for a UEFI Class 2.3.1 system because older OS like MSDOS and XP and Vista etc are Not supported on such machines.  Secure Boot is not an option for MSDOS WIN31 WIN95 WIN98 XP Vista and never will be.

If you have to support old OS I would recommend finding and rounding up Optiplex GX620 machines in the MINI Tower variety.  They are new enough to be able to transition to windows 10 and Old enough to support every OS on earth including MSDOS and WIN95 WIN98 etc.

I have clients that have Elevator controllers that need PS2 and Serial ports as well as MSDOS support from 1981 that need optiplex models that support WIN08SE msdos mode with XP in dual boot mode.

You dont get INT13 msdos support on UEFI systems and never will.

windows xp has 64-bit