BdAPIs
Get divisions, districts, and upazzilas of Bangladesh
Provides fast and accurate IP geolocation APIs along with security checks and confidence area.
BigDataCloud API is a free Geocoding API that requires apiKey authentication, is served over HTTPS and has unconfirmed CORS support.
Everything you need to build with BigDataCloud APIs. Official SDKs, API reference, guides and documentation.
Details from bigdatacloud.com.

Unified API suite · now live
Geocode an address, validate an email, track a flight or pull stock data with one account, one dashboard and one API key.
Get divisions, districts, and upazzilas of Bangladesh
Convert British OSGB36 easting and northing (British National Grid) to WGS84 latitude and longitude
The BigDataCloud API is provided by BigDataCloud (bigdatacloud.com). Everything you need to build with BigDataCloud APIs. Official SDKs, API reference, guides and documentation.
Yes. The BigDataCloud API is listed in the Geocoding category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
Yes. The BigDataCloud API uses apiKey authentication, so you need to register for credentials before making requests.
CORS support for the BigDataCloud API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The BigDataCloud API is served over HTTPS, so it's safe to use in production.