Mac from Shopify here! Thanks for posting this question. I’m happy to help out.
If you have not purchased a domain directly through Shopify, then it is not possible to change the IP address. For instance, if you use a third-party domain, then Shopify's fixed IP address is 220.127.116.11. However, If you buy a domain through Shopify, or transfer your domain to Shopify, then your domain can switch between any of the following IP addresses at any time:
18.104.22.168 to 22.214.171.124
I would also suggest reaching out to your VPN provider to see if the IP address can be whitelisted.
Furthermore, feel free to check out our FAQ and managing domains sections on our Help Center to learn more about how to edit your settings and connect your domain.
Let me know if you have any questions!
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