I want to add a node like here but when I mount Pendrive I received an error like this:
this kernel requires an x86-64 cpu but only detected an i686 cpu
I have some old HP Compaq's with Pentium 4 HT and I can't add this computer.
There's currently no USB image for i386 but it is in progress of being created. Another option for you would be to create a USB Disk of the Ubuntu Server ISO and select:
"Multiple Server Install with MAAS"
Then proceed until you find yourself with
"Install or Enlist with Ubuntu MAAS Server"
And select one from the list or input one.