Replacing Earpiece / Ear Speaker only

Hello,

my ear speaker stopped working after replacing the display. I guess I broke something oder cut a cable. Face ID and TrueTone works fine. I bought this piece and replaced it (https://i.ibb.co/CbHD41d/14-F19163-ABDC-...) but it looks like you cant just change these parts because Face ID stopped working.

After research I found out that I should only change the earpiece without the cable. How can I do that? Read something about soldering. Which parts needs to be soldered?

And how possible is it that my earpiece will work again? I guess if I cut or broke the cable then Face ID and Auto Brightness would also not work right? I guess I only need to replace this part (https://www.repairsuniverse.com/products...)?

I just cant understand why Face ID and other things work with the old one but not the ear speaker.