Is there a way to use a mobile phone as a boot stick?

So I would like to install Linux Mint on my laptop in addition to Windows 10. But unfortunately I don't have an empty CD or a suitable 8GB USB stick. The only thing I have is a USB that has 3.7GB of free space.

For this reason I want to use my cell phone as a boot stick. Unfortunately my phone is not rooted and the stupid Android can only transfer files with MTP.

Without root it won't work, but small ones e.g. You can get 8gb sticks at amazon for less than 5 euro

Yes, but I want to do it best today.

Would be a bit overkill, but you could overwrite an external hard drive with it and use it as a "stick", if you don't have any lying around, maybe an 8GB partition on the hard drive that is overwritten with it, but have not had any experience with the latter, and it could be that he doesn't find it blunt

This is not possible because all data is lost when a storage medium is made bootable… You can also get by with less than 8GB if you want to install the system and not use it as a live system. The 3.7 GB USB stick is sufficient, but save the data on it beforehand. In a pinch, just buy any stick, you can get it for a few euro in the supermarket…