Can not get VM license from ftp server via vdom root

Hello, I am trying to activate new Fortigate KVM-VM image using license via ftp server.

After configuration of port1 (port1 has ip number 10.10.10.10), I use followed command

 execute restore vmlicense ftp FGVM0100000XXXXX.lic 10.10.10.1

On My ftp server I got mesage Transfer complete, and also I saw that content of license gone through fortigate  network interface. But after this command I got 

This operation will overwrite the current VM license! Do you want to continue? (y/n)y

Please wait...

Connect to ftp server 10.10.10.1 ...

Then after 10 minuts it terminate with command:

Can not get VM license from ftp server via vdom root. Err code: 5. VM license install failed. Command fail. Return code -28

So it looks like timeout. I didn't configure anything rather than port1, If it can be some firewall issue (in example cut a packets from ftp?).

Also I had another question, is it possible to upload license using FortiOS REST API?

Edit: I used tftp rather than ftp server and using command 

 execute restore vmlicense tftp FGVM0100000XXXXX.lic 10.10.10.1

I got:

Do you want to continue? (y/n)y

Please wait...

Connect to ftp server 10.10.10.1 ...

#

Get VM license from tftp server OK

VM license install failed

Command fail. Return code -651

Maybe something about this?