Forwarded packets information

Hi guys,
I want change some things and I have what should be a simple question.

So, we have some sites connected by MPLS and all routers in them are managed by ISP. Connections from these sites that goes to the internet will be forwarded to the internal IP of a firewall and this one will route it to the outside. This will be the only point of exit.

On one example the communication travels like this: -192.168.30.10 -> .. -> 192.168.0.254 -> 192.168.0.251

192.168.0.254 is the IP of the router connected to MPLS in the network where the firewall is, the one that will forward the packet to the firewall (FW is 192.168.0.251).

When communication is made back by the firewall it will deliver it to 192.168.0.254, that is the IP that forwarded the packet. Is this right?

TLDR: Pretty much the doubt is on the information that a forwarded packet has. If i understand correctly the firewall when receiving an "answer" from the internet will deliver it to the IP that forwarded the packet to it, not the source of the connection.

Thank you.