Transitioning from one career to another can be tricky. The main goal should be showing that you can do the job if you get the job. Employers want someone that can solve the problems that they have. They look at your resume and try to guess whether you can do the job or not.
To show product management abilities and skills, do product management in an aspect of your life, like at your current job, as part of your hobby, or in your community. You’ll get asked about past product management experiences during interviews, so think about the experiences you already have and how they relate back to product management. You might want to think about experiences where you’ve had to communicate across an organization, solve problems, manage a team, etc.
If you already have the skills but not the title, make sure you promote those skills in your resume and during interviews. Even if your exact title isn’t “Product Manager,” you will have an advantage if you have the skills necessary to get the job done.
It is important to show that you have the skill set to become a good Product Manager. Connect the dots between the work experience you already have and the skills you’ve developed, and how those skills apply to a Product Manager role. During interviews you will get asked why you think you’ll be able to do the job if you don’t have any experience, and you need to demonstrate and explain that you have the core skill set necessary for the role and are getting up to speed quickly.