Updating Tracking Number from Drop Shippers

I’m just starting out with Wix, and am currently looking to ink deals with drop ship suppliers to ship products that I sell. I have a feeling they’re OK receiving emails, which Wix supports OOTB, for them to fulfill. However, I can’t seem to find a method for updating the tracking number so the customer is sent the tracking email – besides typing it by hand. I did find the following API to update tracking info ( https://dev.wix.com/api/rest/wix-stores/orders/update-fulfillment ) and I had two ideas I was hoping to run by the Wix community before pursuing further:

A) Write an external app to parse email responses from fulfillment vendors for tracking info, then call API mentioned above.
B) Create a password protected Wix site with a webform, use Corvid on the webform to call that API after the fulfillment vendor pastes the shipping info into form.

For either, it’s unclear if calling the API will trigger the OOTB email to the purchaser (customer). I also think I could modify the outbound email to the fulfillment vendor to have the URL for Option B, with a URL argument pre-filling the order ID into the webform. But I don’t know if this is possible, and I can’t see a way to edit the email the fulfillment vendor receives.

I also thought about using automations, but there doesn’t seem to be an option of firing off even tasks or workflows based on incoming emails from my drop ship fulfillment vendors.

Mostly, I’m worried I missed some sort of basic method of updating the shipping tracking number automatically. It seems silly to ask my small suppliers to sign up for Modalyst just so I get tracking numbers back. I plan to work directly with small businesses, many of whom leverage Shopify for their own stores.

Any guidance in this space is really appreciated. I’d like to avoid the manual labor of updating tracking numbers from emails. I also wouldn’t mind offering my SMB drop shippers an easy portal to mark a product ‘shipped’ that ties into my Wix orders. These companies are so small, API integration between their system and mine is likely too much to ask, and also asking the dozen or so companies to all use the same platform (ex. Modalyst) is also unlikely – plus eats into my margins.