How to run javascript on server

Hello,

I hope it is OK to ask about this subject here.

I am using nopCommerce 4.0 with source.

I'm considering writing a plugin for my website to do API calls to my product supplier.  The API calls require a key issued to me by my supplier.  I thought I could write a javascript ajax call to send the API to my supplier's server.

I am being cautioned by javascript experts that it is not a secure way to send a key with my API call in javascript.

Does anyone know how I can make my javascript run from a server?

Thanks,
Tony