I've purchased a second hand Pixel 6a, codename: bluejay.

I am looking at running LineageOS on it, perhaps not immediately though. Here are the builds. Here's the install guide.

First I needed to unlock the bootloader. Here's what I needed to do:

• Activate developer mode by tapping the build number seven times.
• Enable USB debugging; the device will ask to trust your computer.
• Now, the developer options will display an option "OEM unlocking".

The 'OEM unlocking' option controls whether the bootloader is locked. This determines whether you can flash untrusted software onto the device using the fastboot tool. Boot into the bootloader using adb -b reboot bootloader.

I started up my device without connecting to any networks. When I started it, the 'OEM unlocking' option was greyed out. I read around the issue, and it seemed that there was a chance I had received a secondhand Verizon handset. Secondhand Verizon handsets are permanently OEM locked, which means you must always run stock firmware on them. However, in reality my handset was not one of these. A phone with an unlockable bootloader is referred to as 'factory unlocked' (contra 'carrier unlocked'). My handset had been sold as 'factory unlocked', so should be fine.

In fact, all I had to do was to allow the handset to update as much as possible, ensuring I had the latest security updates for Android 16. Then, factory reset the device. Having done this, the 'OEM unlocking' option un-greyed itself after re-setting up and enabling developer mode. So it seems that it may require not only a reset, but also a complete update.