What are the steps to process a Work Permit while on a Tourist Visa in Thailand?

Hi Everybody!

I need some guidance about Work Permit.

I got a Job Offer while I am on a Tourist Visa here. They explained me that for them to start the Work Permit process, I need to leave Thailand for at least 7 days, since they will do it under WP3.* (never heard about it)*

After that, they will PDF me the WP3, and only then, I can ask for an appointment in KL Embassy to request a Non Inmigration B visa, where it will take 2 days this process.

Unfortunatelly, the HR lady didnt seemed to know much about the whole process and that makes me Doubt about it.

My question is, Is there another way to process the Work Permit while you are in Thailand? I know you must leave to switch to Non-B Visa, but first time that I hear about 7 working days for WP3.

Thank you for the advices and suggestions!