Based on the search term "TWRP 3520 download top," it is highly likely you are referring to the , where the TWRP version 3.5.2_0 is a prominent release, or potentially the Realme 5/5i/5s (codename "RMX1911") .
Rename your downloaded file to twrp.img for simplicity. Run: fastboot flash recovery twrp.img
adb reboot bootloader fastboot flash recovery twrp-3.5.2_10-0-[device].img fastboot reboot
Immediately after reboot, hold Volume Up + Power to enter TWRP.