How can I sync an original iPod Nano?

I am trying to sync an original (1st gen) iPod Nano with iTunes 12.9.5.5 (on Mojave). Is this a lost cause?

When I connect it, I can see the tunes stored on it, but I don't have write permissions to add or delete content.

In the left-hand panel, the device appears, with 3 sub headings for Music, Audiobooks and a playlist called iPod Nano.

Under File > Devices, there's only an option to "Transfer Purchases".

I've tried to find a way to restore the device to factory settings, but I've only come across very misleading articles that tell me how to reboot it (or sometimes, button combinations that do nothing at all.

Any suggestions?