This is a simple "currency scale" to register with Charts.js

CurrencyScale.js

class CurrencyScale extends Chart.LinearScale {
	static id       = "currency";
	static defaults = {
		currency : "USD",
		locale   : "en-US"
	};

	getLabelForValue(value) {
		return this.formatCurrency(value);
	}

	generateTickLabels(ticks) {
		ticks.map(tick => tick.label = this.formatCurrency(tick.value));
	}

	formatCurrency(value) {
		return new Intl.NumberFormat(this.options.locale, {style : "currency", currency: this.options.currency}).format(value);
	}
}

you then can simply add the type to your scales config object, after you registered the scale:

Chart.register(CurrencyScale);

...

new Chart(ctx, {
    options : {
        plugins : {
            scales : {
                y : {
                    type        : "currency",
                    beginAtZero : true,
                    currency    : "EUR",
                    locale      : "de-DE"
                }
            }
        }
    }
});