The working class includes those who earn their living through wage-paying (hourly) jobs, typically involving manual labor or service work without poatsecondary education requirements. They tend to have modest property ownership, and make close to minimum wage with limited benefits. Working-class jobs are predominantly in the service sector, including retail sales, clerical work, food industry positions, and manual labor.
Which definition of working class are you using that includes doctors, lawyers and engineers?
Its a general definition of the phrase. There will always be exceptions. There is still no evidence that anyone considers doctors, engineers, lawyers etc to be part of the working class.
They are generally considered to be part of the professional class. More have become beholden to corporate structures as America descends further into late stage capitalism, but they are still not generally considered part of the working class.
Most Amazon / Walmart workers, Uber drivers, fast food workers etc. would likely scoff at the idea of considering those professions to be working class as they are.