The PMP Role Delineation states that candidates for the PMP credential:
• Perform their duties under general supervision and are responsible for all aspects of the project
for the life of the project
• Lead and direct cross-functional teams to deliver projects within the constraints of schedule,
budget, and scope
• Demonstrate sufficient knowledge and experience to appropriately apply a methodology to
projects that have reasonably well-defined project requirements and deliverables

The key phrase here is “under general supervision”. When I first became a Project Manager 25 years ago, my manager, himself an experienced Project Manager who moved into a management slot supervised my efforts. Such on the job training is the best route to take to gain the needed experience. Smart companies create internships and mentoring opportunities.

One way to convince your manager you are ready for such an “apprenticeship” would be to earn the CAPM - Certified Associate Project Manager first.

While its an unfortunate truth, there are also still companies which create the “knighted” Project Manager — you get a copy of the MS Project documentation (if you’re lucky!) and are told to “go forth and manage”.

Either way, you can still earn the necessary experience, even though just working on projects isn’t any longer sufficient.