This is where you become a plumber. There are two common clog locations:
Once you can blow through the hose by mouth (gross, but effective) or see water running freely through it with a garden hose, the clog is gone. how to unclog a dishwasher drain hose
Run the dishwasher on the shortest cycle (Rinse only) without any soap. Let it fill for 2 minutes, then force it to drain. This is where you become a plumber
The drain hose is usually located at the back or bottom of the dishwasher. It's a flexible hose that carries wastewater from the dishwasher to the drain pipe. You may need to consult your dishwasher's user manual or look for a diagram to find the exact location of the drain hose. Let it fill for 2 minutes, then force it to drain
Water takes much longer than usual to leave the machine.