AFP server

https://launchpad.net/ubuntu/focal/+package/netatalk

apt-get install install netatalk

nano /etc/netatalk/afp.conf

[Homes]
 basedir regex = /home

[Otras carpeta]
 path = /path/to/directory

Apple Time Machine share

[My AFP Share Name]
 path = /path/to/directory
 time machine = true

Setting the guest account

[Global]
 guest account = pi

systemctl restart netatalk