[redshift]

the linked github page.

If you're looking at a GitHub page, then you're probably looking at the Tangara Companion, which is the software that (most easily) updates your Tangara.  You download that and install it like you would other software, so on Windows running the .exe (e.g. tangaracompanion-v0.4.3-windows-x86_64.exe), or on Mac unzipping the file and copying the .app to your Applications folder.  If you're on Linux, let us know which distribution, because there are a few ways to install it.  (Some community members have packaged it for various Linux distributions, or you can use the official Flatpak package, which can work anywhere.)

Then you download the latest .tra firmware file from Codeberg; as of today that's this file.

Then you run the Tangara Companion, click the Firmware Update tab, and select the .tra file you downloaded, and it will update your Tangara.  (It takes a couple minutes.)