I don't know if Airtable uses static IP addresses that you can reliably whitelist.
I would recommend making all of your API calls from Make, which publicly publishes their list of IP addresses that you should whitelist.
Not only does Make offer native support for Airtable (and 1,400 other apps), but it also lets you craft your own custom API calls using their HTTP module.
There can be a bit of a learning curve with Make, which is why I created this basic navigation video for Make, along with providing the link to Make’s free training courses. There are also many Make experts hanging out there who can answer other Make questions.