If you have a Davis station that is uploading to the WeatherLink service, you can add up to six "shares."  Steps would be, log into your WeatherLink account.   Click on "Share & Uploads," then click "Upload" and finally "Add Upload."   Choose the "CWOP" service, then enter your amateur radio call sign and your weather data will be sent to APRS.   You don't need to be registered in the CWOP program to send data to APRS.   But, if you are sending data to APRS, you can register into the CWOP program.

If you are not using a Davis station or don't use Weatherlink, there are several scripts to upload data on Github.  Here is a search: https://github.com/search?q=CWOP+APRS

Kind Regards,

Ken Clifton