Two Chart.js chart types use radial scales: radar and polarArea. Radial charts that have a single scale are configured with the properties listed here. Some properties are similar to the properties used in Cartesian scales, but they have fewer configuration options:

These properties are used directly inside the options.scale object. For example:

options: {
     scale: {
         ticks: {…},
         angleLines: {…},
         gridLines: {…},
         pointLabels: {…}
     }
 }