The Raspberry Pi 1, 2, 3 and Pi Zero / Zero W all have two UARTs (PL011 + mini UART). The Raspberry Pi 4 and 400 have six UARTs (5 x PL011 + mini UART). This is from the official documentation.
I have been unable to find information about the Raspberry Pi Zero 2 W. There is however a difference between Zero W (Buster) versus Zero 2 W (Bullseye) when I run dtoverlay.
pi@rpi-zero-w:~ $ dtoverlay -a | grep uart
midi-uart0
midi-uart1
miniuart-bt
uart0
uart1
uart2
uart3
uart4
uart5
pi@rpi-zero-2-w:~ $ dtoverlay -a | grep uart
midi-uart0
midi-uart1
midi-uart2
midi-uart3
midi-uart4
midi-uart5
miniuart-bt
qca7000-uart0
uart0
uart1
uart2
uart3
uart4
uart5
Does this mean that the Zero 2 W also has 6 UARTs? Can I map some of these out to GPIO pins?