Something like this: https://www.amazon.com/dp/B007CZ6PD2

I just noticed that you're using a mains-powered pump, so don't splice its wires directly. Instead, insert the float switch on one of the wires between the QT Py and the relay.

A condensate safety drain switch is appropriate here.

Something like this: https://www.supplyhouse.com/Beckett-Pumps-1502UR-Float-Safet...

or

https://www.supplyhouse.com/Little-Giant-599124-ACS-3-Auxili...