Plugin servers
Put the plugin jar in the server’s plugins folder.
SkinsRestorer
SkinsRestorer is a free plugin and server mod. It shows real skins on offline mode servers, and players can change their skin with one command.

/skin set xknat
Applies the skin of the Minecraft account xknat.
Pick the software your server runs. Each guide covers where the file goes and how to check that it works.
Put the plugin jar in the server’s plugins folder.
Install it on the proxy and on every backend server.
Put the mod in the server’s mods folder. Players install nothing.
The plugin and the Fabric and NeoForge mods are separate downloads. Modrinth and GitHub releases have every build.
Players type these in chat. Server staff decide who can use each one with permissions.
Wear the skin of any Minecraft account.
Wear a skin from a PNG link.
Pick a skin from the in-game menu.
Go back to your previous skin.
Fetch the latest version of an account skin.
Use your account skin or the server default.
Bug reports and pull requests go to GitHub. Questions about setup or config get answered in Discord.
Short answers. The documentation has the details.