How does this method work?
Starting without capital does not mean spending no resources. Computers, the Internet, and time to learn and look for customers are also resources. Tasks that can be tried without spending money may include editing, translation, simple design or preparing content for the business on a subject you know. Instead of selling a job you cannot do because it is cheap, choose a small and controllable delivery.
Evaluation with a concrete example
Consider a business proposal to edit five product descriptions. Show the first example on the imaginary product you created; Don't feel obligated to do someone else's full work for free. If the scope of work is five texts and one round of editing, write this. If a job planned for three hours turns out to be ten hours, just because it is 'capital-free' does not mean it is a good job. Your biggest expense may be unlimited revisions.
Your first application: what should you have?
Pull out three examples of your current skills, place them in a one-page portfolio, and narrow down your target customer type. Do not accept offers that ask you to deposit money, request a verification code, or use your bank account before you can work. The first goal is to see real customers respond to a job that you can deliver with free tools.