Unbricking RT-AC5300 using Serial

Hello,

I had a similar post on the other forum but no one responded.

I bricked my router to the state where no CFE is working nor the Asus recovery method nor 30/30/30 the router is in a loop of restart every 3 min.

I bought the USB to Serial cable & planning on restoring the original firmware this way but I don't have any command lists to use.

Can anyone provide me with a guide / help file or documentation on how to restore using which tools / commands?

Thanks in advance