Windy plugin extends functionality of Windy.com. They are developed in js and published as npm packages. Your Hello World will be running in less than 5 minutes.
There is a fetch error:
The 'Access-Control-Allow-Origin' header contains multiple values '*, *', but only one is allowed. Have the server send the header with a valid value, or, if an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.
Header set Access-Control-Allow-Origin "*"
Actually you cannot; Windy maps use the projection EPSG:3857 – Pseudo Mercator, aka. Web Mercator, Google Web Mercator, Spherical Mercator, EPSG:900913 or WGS84 Web Mercator; it is a variant of Mercator projection used as standard in Web mapping.
Covered area: -180° W, -85°.06 S, 180° E, 85°.06 N
What you need is EPSG:4326 – WGS84
The World Geodetic System (aka. WGS) 84 is a standard Coordinate System for Earth, a standard Spheroidal Reference Surface (aka. Datum, Reference Ellipsoid or SRS) and a Gravitational Equipotential Surface (geoid) that defines the nominal sea level. In common language it is assimilated to a cartographic projection and largely used to represent large scale maps. It is used as a standard in GPS, where Geographic Coordinates are not projected: they are provided in longitude and latitude degrees.
The well-known GCS WGS84 (aka. EPSG:4326) is mainly used to handle (raw) data coordinates (Longitude, Latitude, Altitude) on Earth. As a language abuse, it is also known as a projection.
Covered area: -180° W, -90° S, 180° E, 90° N
Reprojecting the original map from EPSG:3857 (the native projection of OSM source) to EPSG:4326 is still possible, you should do it via Leaflet framework...