Amateurs write when they feel like it. Professionals write because it’s their job.
Of course, the fact that you’re being paid doesn’t change the act of typing on your keyboard in the moment.
Amateurs become professionals before they gain a job title that says so. Not the other way around.
P.S. you can replace “write” with any task and it still works.
At first this sounds oppressive, but soon you realize that it’s freeing. You don’t need to feel inspired to do great work. You don’t need to have a perfect set up to perform. You can do great work because you’re a professional.