peugeot 406 oil pressure insufficient

Yesterday I went to the shopping center for 1 hour, I came in front of the house, I parked the car (there was no problem until here.) Then I got into the car again, opened the ignition, the oil lamp was on + the stop lamp was blinking and it was giving a warning sound. it turns out (my oil pressure insufficient) is my 406 2.0 engine.
How could I fix this malfunction?

insert the pole press, wait and plug it, the master must look