Dear Will,
Good day!!
I understand your concern and to my search, Office Scripts doesn’t support sending the HTTP requests to a external web API but to get the detailed information related to Office Scripts, I suggest you post your concern in the Microsoft Power Automate Community - Power Platform Community to get the detailed information from the experts.
Apologies for redirecting you to different community as the members in the category posted focus on the users with the Microsoft 365 concern and have limited knowledge on the Office Scripts, so to get the fast and better assistance, we have redirected you in the correct path.
Appreciate your patience and understanding. Have a great day!!
Best Regards,
Sophia