OK now you know that uart2 is not available. You should remove uart2 from the config.
Try uart5! add this line into /boot/config.txt
The TX will be GPIO12 and RX GPIO13
B.T.W. uart3 use the same pin than i2c and uart4 the SPI.
The simple method to check if it works will be to install a serial terminal like minicom.
sudo apt update
sudo apt install minicom
Try to connect GPIO12(pin32) and GPIO13(pin 33) together.
Then if you run minicom it should echo what you type. if you break the connection between GPIO12 and GPIO13 it shouldn't work.
If it works then try to connect serial0 with uart5(ttyAMA1). TXD0 to RXD5 and RXD0 to TXD5. Use two terminals with specific minicom on them
The FIrst terminal with the previous minicom command and the second with
I assume that you disabled the serial login on serial0.