Query amateur radio repeater listings for a region from RepeaterBook's Export API

Steps

1. Submit the public token-request form at repeaterbook.com/api/token_request.php to apply for API access, specifying whether your use is centralized/server-side or a distributed client app, and whether it is commercial or non-commercial.
2. Once approved, obtain your issued token (either a server-side app token or a user-generated per-application token) and send it in the X-RB-App-Token request header on every call.
3. Set a descriptive, unique User-Agent header (application name/version plus a contact email or project URL); generic or default User-Agent strings can be rejected.
4. For North America, send a GET request to https://www.repeaterbook.com/api/export.php with filters like state_id, county, callsign (supports % wildcards), or frequency; for the rest of the world, use https://www.repeaterbook.com/api/exportROW.php with country/region filters.
5. Handle 429 Too Many Requests responses by backing off immediately, and handle the documented JSON error codes (auth_missing, auth_invalid, ua_mismatch, rate_limited, etc.) distinctly rather than blind-retrying.