Collect email addresses into various lists, based on category selected on signup form

Hi there,

how can I have service providers sign up with a membership site (using Memberstack), have them choose from a list of categories they want to be listed under, and then have their email address added into a designated list, based on the category that was chosen during the sign up process?

Example. Let’s say there are 10 categories of services a business can sign up under. Peter Peters chooses to be in category 3. So I want his email address to be added to email list #3. John Johnson chooses category 7, so his email address needs to go on email list #7. How can I do that? Can I do that within Webflow, or do I need to use third party tools for that, like Zapier?

Thanks so much advance,

any help is greatly appreciated.