Ubuntu 20.04 and it's offspring (Xubuntu, Mint...) neglected to add the repositories for the GUI which makes it super simple to use.
But these instructions should also make it very simple to do. No not as fast or easy as the GUI but if you need it it's pretty fast and super easy. 

This is for sharing on your computer NOT SETTING UP A SAMBA SERVER.

Open your favorite Terminal then type or copy and paste these in.
First Stop Samba:
Type or copy and paste this hit enter: sudo service smbd stop

Then back-up the original file just in case.
Type or copy and paste this hit enter: sudo cp /etc/samba/smb.conf /etc/samba/smb.conf_backup

Then edit the samba config file.
Type or copy and paste this hit enter: sudo nano /etc/samba/smb.conf

You should see something like this.

This IS A WORKING CONFIG FILE COPY & PASTE, change the name of your computer, change hosts allow to your IP number, add your share folders. Add your username, add your password and your Samba will work. Tested on Linux to Linux. REMOVE the # if you want to use that part I don't add private area's to Samba. I only like sharing folders I add and printers. You can also remove every line with a # those are just notes or instructions.

[global]
netbios name = AMD-BEAST (YOUR COMPUTER NAME HERE)
security = user
workgroup = workgroup
server string = %h server
log file = /var/log/samba/samba.log
max log size = 1000
dns proxy = No
hosts allow = 127. 192.168.1. (192.168.1. should match first 3 groups in YOUR ROUTER)
hosts deny = false
cups options = raw
printing = cups
printcap name = cups

[printers]
comment = All Printers
path = /var/spool/samba
browseable = yes
writable = no
guest ok = no
public = no
printable = yes
locking = no
strict locking = no

[print$]
path = /var/lib/samba/printers

#[Public Directory]
#path = /Public/Files
#guest ok = yes
#read only = no
#browseable = yes

#[Private Directory]
#path = /private/files/
#valid users = beast
#read only = yes
#browseable = no


# Add the drive or folder/s you would like to share "[software] (The Share Name)"
# To share just one folder on the drive it would look like this path = /media/YOUR USERNAME/software/linux
# You can copy and paste the settings below and just add you share name, username, the drive or folder you want to share.
# Add as many entries as you would like to share leaving a single line space between each entry.

[software]
path = /media/YOUR USERNAME/software/software
# path = /media/Bill/home/pictures 
writeable = yes
browseable = yes
valid users = YOUR USERNAME 
# if you have more then one user it should look like this: valid users = jim, joe, allen, bill
# You will need to recreate this group for each shared folder.

Then hit the Ctrl key + x when it asks you to save the file say Y = YES
Then it will ask the name to save it as don't change anything just hit enter.

Then run these:
Restart Samba:
Type or copy and paste this hit enter: sudo service smbd restart or sudo systemctl restart smbd

Add user and password to Samba: (If you have more then one user run this for each user)
Type or copy and paste this hit enter: sudo smbpasswd -a YOUR USERNAME
Type in a password (it can be your log into linux password - hit the enter key)
Retype password hit the enter key.

You should see this:
Added user YOUR USERNAME.

Go to Networking and look for the NAME OF YOUR COMPUTER
All done you should be able to see and access your shared drives and or folders on any Linux, Windows 7, 8, 8.1 computer, laptop, tablet.

This should work in any OS if you don't see your computer listed. In EVERY OS BUT WINDOWS 10 you will only need to do it ONE TIME.
Windows 10 as everyone knows is garbage if you don't see your computer listed like always.
Click on Network, in the address bar type in the name of your computer hit enter.
Like this: \\COMPUTERNAME
It is Windows 10 so you may need to do it three to five times. Every time Windows 10 will say it's not there don't give up, don't bother with trouble shooter just keep pasting it in hitting enter. Then like magic the computer it couldn't find will appear! LOL Windows 10!

As always any questions just ask!