Install OpenWrt on a Speedport W 723V Type B

Hello there,
I hope I'm in the correct topic here?

So, I have an old Speedport W 723V Type B found and wanted to reuse it with OpenWRT, but there is no build available for this device, as far as I could see.
Does anyone know, how I get a running build for this device and how to install it?

Thanks for your help in advance :slight_smile:

this device is not supported by openwrt
https://openwrt.org/toh/t-com/spw723vtypb

Thanks for your reply @khokooli,

Yes, I saw that page about this device. But I it says yet, that's why I'm asking.
And it says, that OpenWRT could get built on nearly every device by your own. With that in combination I thought there would be a way, how this device could get supported. But my knowledge in those topics is too low, to do those things on my own.