By default, the IP address of a trading account can change and can be different for each account.
If you want:
An IP address that remains constant for each trading account but is shared among multiple trading accounts, you need the 'Static Shared IP'
with Subscription Plan: 2 EUR/account/month
with Prepay Plan: 0.07 EUR/account/day
A unique, unchanging IP address assigned exclusively to each trading account, you need the 'Static Dedicated IP'
with Subscription Plan: 5 EUR/account/month
with Prepay Plan: 0.17 EUR/account/day
You can select the IP Attribution mode in the Account Settings or assign the Subscription Plan with the IP Attribution mode