I'm on a Pixel 6a.
Pixels do not support changing individual icons, nor icon packs at all. You will need a third party launcher like Nova Launcher to swap icons.
On Nova launcher, simply long press the app icon on your home screen, tap the icon in the edit window, and it will let you choose from the icon packs you have installed, or from the photo gallery or file system. This applies to PWA apps as well.
Copy that. I think there might also be a way to make a custom app launcher shortcut as a widget via some 3rd party apps, but I can't remember which ones allow for this.
I'm trying to avoid nova launcher ever since they sold to a 3rd party.
Figure I'll just wait it out until a new icon is selected for the voyager rebrand!
Edit: So I just answered my own question! I remembered how to make a custom app shortcut with a different icon pack or your own image on Android, and you can choose the app name as well! Use this app: Shortcut Maker: Play Store; add a new widget to your home screen and select Shortcut Maker > shortcut (standard). Select wefwef, and customize away.
Here's my result for example:
Edit #2: while this works, it seems that when you use the shortcut created this way, it restarts wefwef and you lose where you left off. Bummer