Grind is too coarse. Turn the grinding adjustment dial one click anticlockwise while the grinder is running. Make two coffees. The change only shows after two cycles. Repeat one click at a time until it's right.
If adjusting the grind doesn't fix it, your beans might be stale or oily. Use fresh, dry espresso beans. As a test, bypass the grinder. Use pre-ground espresso in the funnel. If that makes a good coffee, your beans or grinder setting are the problem.
Keep the infuser and spouts clean. Blockages can mess with pressure and extraction.