Need to connect waste pipe of washing machine. The waste pipe is the white one connected to the gray one.
The gray pipe underneath is not in use.
What connectors would be best? Where to cut?
it's awkward there because the waste run is horizontal, a standpipe there would limit how far back you can put your washing machine and could create some smells with the waste water entering the standpipe trap.
Ideally you want to take the waste through the cabinet side into a spigot under the sink waste. Is there a reason you can't?
Or drill a new hole out and install a new stand pipe in the next cabinet and take the w/m waste through the cabinet side.
There are also compression spigots that you could use instead of that coupling like these.
Bear in mind though that a spigot straight into that pipe wouldn't have a trap so you could get foul smells coming back into your washing machine.
That's a novel use for a rad tail extension on the cold washing machine connector
Insert a tee where convenient and reduce down to 32mm. Hose can then be jubilee clipped to spigot similar to above and spigot connected to 32mm waste with straight compression coupler. Arrange hose with dip so part retains water and prevents foul smells.