then connected my FP 4
As far as I know, it is also important to lock back the bootloader, so the device would be secure. Here you can find the steps how to finish the installation for fairphone 4: Unable to install on new Fairphone 4 via Easy/web installers, and security patch dates do not match on latest builds - #10 by mnd
It requires additional software to be installed. A tip: I used a separate computer to not bloat my main computer. Be sure to update phone’s operating system to the latest version (Android 14 at the time of writing) before locking the bootloader.