Please make sure that you are using the latest version of Dokan plugin (v1.4). If you are using the latest version then please provide me the URL of your site let me check that problem by signing up as a customer.
Thank you for reply.
I'm indeed using latest plugin (dokan v1.4) and latest dokan theme v2.1
I had tried every possible ways at “Dokan -> Settings -> Selling Options” but no avail.
Up til now, the only way I can make a customer become seller is to manually set the user (customer) to become seller, which is not what I expected. I was really expecting the customer could migrate their role to become seller, without me as admin to intervene. I reckon this is supposedly a basic feature for a multi-vendor solution?!
PS. I don't have public URL. I am just testing dokan in my home environment.