How can I use external hosting and SSL for my store's webhooks without additional costs?

[clebosky]

Hello,

I'd like to use an external hosting to perform processing on my server following the various possible actions in my store (thanks to shopify webhooks). For this, I bought a domain name and hosting from GoDaddy.

I wanted to use the domain name for the store, so I made a redirection with the DNS and it works. However, I'd like to be able to use my hosting to receive the webhooks I configured on the admin panel, and process information on my side.

I thought about the possibility of a sub-domain. However in this case, how to make it work without having to buy a SSL certificate dedicated to this sub-domain? (webhooks must point to an HTTPS endpoint).

Is there another solution through Shopify admin configuration ?

If not, is there a possibility to exclude a particular folder from DNS redirection (on Godaddy) ? For example, mywebsite.com and every folders inside would be redirected to Shopify but not mywebsite.com/files/, it would stay connected to the GoDaddy hosting.

The final goal is to use both the store and my external hosting without multiplying the certificate costs, regardless of the domain/subdomain configuration.

Thanks for your help.