It's not an app so it won't show up there, you should be able to install it manually in the command prompt with:

sudo apt install android-sdk-platform-tools-common package

But that's unlikely to let you proceed with the installation without hiccups since your browser is still a flatpak. Do you have another Android phone in reach by any chance? If it's relatively modern it's likely you can use that as the host device. Simply open the web installer there and connect that phone with your pixel.

    spring-onion I have installed this package now, I must of missed a bit of the command. I'm thinking I will uninstall Brave and re-install as a .deb?

      Rand-Uzer I do have a perfectly functioning Samsung A04, these are getting a bit old now.
      I will try a .deb terminal install of Brave as I've not used it for anything so no big deal to uninstall

      Sounds good. If it doesn't go anywhere I would definitely try with the Samsung, from my brief research it might fulfill the requirements. If you go down that route, the only difference regarding the install process will be that you will have to keep tapping reconnect on the Samsung during various steps of the installation.

        spring-onion I just installed Brave via terminal so I will try again and keep you posted. If no joy I will try the Samsung
        Thanks a lot for the assistance so far, I do feel I'm getting closer (famous last words lol)

        spring-onion One question, do I need to change usb settings for this to work, eg transfer files or in developer menu verify apps over usb? With the Samsung

        spring-onion Well I have got further, I'm at download release and I got this ..."Error undefined"

        spring-onion On the Samsung? Not even close to that, looks like I will need to do a heck of a lot of deleting and transfering., not sure I can get to 32 gigs on the Samsung

        spring-onion Well I deleted all photos and videos, deleted most apps and no way the phone can do it as it's telling me there is only 32 g total storage and I can only get it to 14.3 gb available ...

        How hard is the command line install? Is it copy commands all the way?

        It should be pretty reasonable, just make sure you download and flash the correct release.

          spring-onion Well let me hope and pray I don't brick a brand new pixel 8a or $600 USD down the drain.
          You have been an absolute champion with your help. I will let you know what happens and mark the thread "solved" I hope

            Rand-Uzer If the directions are followed exactly it should be fine. But it is very important not to skip any steps or continue past any warnings. Everything in the installation instructions matters. The instructions say that flatpak browser installs should be avoided because they don't work; the instructions say 32 GB of storage is needed because that much storage is needed.

            Similarly with the CLI instructions: doing what they say should be safe and should work, but doing other things likely won't work and could be dangerous.

              Read the instructions carefully, I'm sure you'll be fine. And use the usb-c to usb-c cable that came with the phone to minimize the chance of something going wrong with the connection.