Changing or adding shipping icons on check out page

Hello.

I am using Opencart 3 and I have journal 3 theme installed.

I have duplicated the flat shipping rate (using a ocmod from this forum). My reason for this is I want to offer an express delivery with DPD and as there is no integration currently, I found this to be the best fix for my issue.

I am unable to find the file responsible for the icons on the check out for shipping.

For some reason the attachment function isn't working on the forum so this is a link to a screenshot of my issue

https://imgur.com/GJGmBAb

I would like to add a delivery icon (one of the trucks) next to my duplicated shipping (DPD Express Rate)

Can anyone point me in the right direction?

Journal->Skin-Default->Checkout

Thank you Virus, and here I was looking through the controller files .