Adding new subscribers to Klaviyo

Can someone walk me through the step-by-step setup of getting a new subscriber from my app added to an email list on Klaviyo? Or, guide me to a resource that explains the process.
I know this is a big ask and I will be so grateful if anyone can help.
Thank you!

You should create a workflow that would make an API call to the Klaviyo.

Here is the link for documentation on Klaviyo page: