Chartjs-How do I add chartjs into a custom plugin in moodle

"chartjs": "https://cdn.jsdelivr.net/npm/chart.js@3.7.1/dist/chart.min"

Seems your path is wrong
you are missing the extension

"chartjs": "https://cdn.jsdelivr.net/npm/chart.js@3.7.1/dist/chart.min.js"