[Vuejs]-Integrating vue-chartjs(version from 2.8.7 to 3.2.1)?

vue-chartjs follows semver. So the “breaking” release is the v 3.0.0
Some things how you create your components have changed.

Just check out the Release Notes: https://github.com/apertureless/vue-chartjs/releases/tag/v3.0.0

There is a migration guide. It is super easy and you should be done in a few mins.