The method is to connect the water source, adjust the nozzle, adjust the water volume, and adjust the spray angle. details as follows:

1. Connect the water source: Connect the water inlet of the irrigation spray gun to the water pipe to ensure that the connection is tightly sealed.

2. Adjust the nozzle: According to the irrigation needs, select the appropriate nozzle and install it on the irrigation spray gun.

3. Adjust the water volume: According to the size of the water flow, it can be adjusted through the water source valve.

4. Adjust the rain gun spray angle: Finally, adjust the size of the spray angle, which can control the spray area and spray range.