This is an official PlotSquared addon which creates holograms by the sign location for plots and, if configured, a player head above it. If you only want to have Holograms, you will need to disable signs in the PlotSquared configuration.
The download is available at Modrinth.
This addon requires PlotSquared and HolograhpicDisplays or DecentHolograms to be installed. You can get them below:
By default, the holograms will contain the text which is by default on the plot signs. The line content, offset and placeholder skulls for special plots may be configured.
Support is available on discord server. If you encounter an issue or want to add a feature, you are welcome to open an issue or raise a pull request.