This is exactly what I did to get files from my computer to my phone! Samba is what got me both directions. 'Samba' is a popular server that follows the SMB network protocol.

Samba really is where it's at. I'll make a small guide. This is for Ubuntu. I am using a Raspberry Pi with an SD card. Nothing too special, since this is just a transitory space for transfering files.

Here's what I do on Ubuntu. You might want to make a new user just for the Samba share, since the SMB username is taking from users on the machine.

# install samba
sudo apt install samba

# allow samba through firewall
sudo ufw allow samba

# make a file for the samba share
mkdir /home/USERNAME/samba

# edit the conf to add the lines
sudo vim /etc/samba/smb.conf

# add these lines to smb.conf
[sambashare]
    comment = Samba on PiHole
    path = /home/USERNAME/samba
    read only = no
    browsable = yes

# set a password for the samba share
sudo smbpasswd -a USERNAME

# start the samba server
sudo service smbd restart

Then, on the iPad or iOS device, add a network location (Files > three dots). You'll need the local IP of your Samba server. The details will be like:

1. Address: `smb://192.168.1.123`
2. Username: USERNAME used to set start Samba on Ubuntu
3. Password: Password set with `sudo smbpasswd -a USERNAME`

There's a bug on iPadOS and iOS where the share will be read-only until you disconnect and reconnect to the server. You may need to do that a few times, or restart your device.