NAT allowing just one ip

General questions
1

Hi is possible to permit preffix x on nat, to just allow 1 ip address of connection for example

IP 172.16.20.20 allowed to access to ip 1.1.1.1 just that

and drop any other request

2

HI

Yes, I think it’s possible .First , you should configure a nat 1-1 with the scr ip / to dst ip and If you want to filter an extra traffic it’s needed to add a Firewall rule:
example:

set nat destination rule 2000 description '1-to-1 NAT '
set nat destination rule 2000 destination address '172.16.20.20'
set nat destination rule 2000 inbound-interface 'eth1'
set nat destination rule 2000 translation address '1.1.1.1'

if you need some firewalls example :
https://docs.vyos.io/en/latest/configuration/firewall/index.html#firewall