I figured this out on my own!
- In the frontend, add a script that generates a JSON file containing an array of icon keys in the public directory
- add script to package.json as its own script, and add it to the yarn build script
- I’m using Next.js so I added an api route to fetch the JSON file
- add customField to Strapi admin
- In custom field, fetch the JSON and map the results as select field options