[zaik]

It's built on OpenStreetMap data, so you can start contributing by clicking the 'Edit' button on openstreetmap.org

Here's the OSM wiki entry on how to map power lines: https://wiki.openstreetmap.org/wiki/Power_lines

[matkoniecz]

See also https://wiki.openstreetmap.org/wiki/Contact_channels - there are active communities using IRC, Discord, Slack, Telegram, mailing lists and other communications tools.

Feel free to join them and ask for help!