Anyone know of a similar plugin (that is supported!)
It looks as though the latest version of this plugin cannot be installed, because it hasn't been updated with Grafana, so does anyone know of a button/switch which has similar functionality, and is maintained?
You could use the Canvas Panel with disable_sanitize_html set to true and enable_alpha set to true ( See https://grafana.com/docs/grafana/latest/setup-grafana/configure-grafana/#panels) You can then move the lever for "Show advanced element types" to on and see an element type "Button" in the dropdown of available elements.
https://grafana.com/grafana/plugins/speakyourcode-button-panel/ could also be used in combination with a datasource, in this way any credentials required to execute the query are stored in secureJson rather than as plaintext.