WhatsApp Business API usage on free shopify theme - refresh

hello all,

I am using Refresh (free) theme for my online store. I have kept a setting of phone number or email while creating customer account. I have seen customers opting for phone numbers. But I received feedback that they are not getting any sms or messages on their phone about order confirmation. I saw an adv about WATI app providing Wati: WhatsApp Business API.

My question is, does this API works on free theme such as Refresh? Is anyone using it?

Thanks,

Kiran - Scentfolio