Download game on USB stick?

I got Borderlands from Epic Games and wanted to install it. However, my laptop has far too little GB of memory, which is why I can't download it. So I wanted to ask if you can load the game onto a USB stick instead and use it on the device. If it is relatively complicated, I would appreciate a brief explanation.

Theoretically, I would not recommend it to you. When installing, games create registry entries on the PC. But if you unplug a USB stick now and put it back in later, the drive letter could change and thereby shoot the installation.
In other applications like Steam, that wouldn't be a problem, since you could search for the file again. But Epic doesn't. In the worst case, you would have to reinstall it completely.

Alright thanks. Would there be another way or do I have to buy a memory card?

You can simply plug an extended memory into the USB port. The WHOLE game has to fit on it. I wouldn't be so sure whether a USB stick was really enough

To install software you need a hard drive or score. Unfortunately, USB sticks only act as removable media. However, it is possible to modify a special driver that Hitachi released a few years ago. So this driver, which is actually only intended for mini hard drives, also works for USB sticks. You can find out more here:

https://tipps.computerbild.de/software/windows/so-koennen-sie-ihren-usb-stick-als-festplatte-nutzen-482217.html

However, it would be significantly more efficient to buy a new SSD or hard drive.

You could e.g. Buy an external hard drive and connect it. This is very similar to the method with the USB stick, but if you leave the hard drive connected almost continuously, the drive letter does not change