How to set up a public IP address on the WAN

Hello everyone,
My internet service provider has given me a pool of public IP addresses ranging from 193.x.x.2 to 193.x.x.5 with gateway 193.x.x.1.
Now I have two problems: basically, the network configuration at the moment is that the router, which is the LAN network from 192.168.88.x, is connected to the wan1 port of my fg100f.
Despite having this pool of addresses, I access the Internet as 84.82.x.x and cannot figure out how to access it as 193.x.x.1. The second problem is that I do not know how to directly set the IP address 193.x.x.2 on the WAN1 port of my Fortinet fg100f.
Does anyone have any advice on how to solve these problems?

Many thanks in advance.