This demo uses imperative chart updates. The generated code is a faithful Angular translation: open it in CodeSandbox to run and tweak.

import { Component, AfterViewInit, OnDestroy, ViewChild } from '@angular/core';
import {
  ChartComponent,
  ApexAxisChartSeries,
  ApexNonAxisChartSeries,
  ApexChart,
  ApexXAxis,
  ApexYAxis,
  ApexTitleSubtitle,
  ApexDataLabels,
  ApexStroke,
  ApexFill,
  ApexLegend,
  ApexTooltip,
  ApexMarkers,
  ApexPlotOptions,
  ApexResponsive,
  ApexGrid,
  ApexAnnotations,
  ApexStates,
  ApexTheme,
  NgApexchartsModule,
} from 'ng-apexcharts';

export type ChartOptions = {
  series?: ApexAxisChartSeries | ApexNonAxisChartSeries;
  chart?: ApexChart;
  xaxis?: ApexXAxis;
  yaxis?: ApexYAxis | ApexYAxis[];
  title?: ApexTitleSubtitle;
  subtitle?: ApexTitleSubtitle;
  dataLabels?: ApexDataLabels;
  stroke?: ApexStroke;
  fill?: ApexFill;
  legend?: ApexLegend;
  tooltip?: ApexTooltip;
  markers?: ApexMarkers;
  plotOptions?: ApexPlotOptions;
  responsive?: ApexResponsive[];
  grid?: ApexGrid;
  annotations?: ApexAnnotations;
  states?: ApexStates;
  theme?: ApexTheme;
  colors?: string[];
  labels?: any;
};

@Component({
  selector: 'app-chart',
  standalone: true,
  imports: [NgApexchartsModule],
  templateUrl: './chart.component.html',
})
export class AppChart implements AfterViewInit, OnDestroy {
  @ViewChild('chart') chart!: ChartComponent;
  public chartOptions: Partial<ChartOptions> = {
          series: [
            {
              name: 'Setpoint',
              data: [16, 16, 18, 21, 21, 19, 19, 22, 22, 18, 16],
            },
          ],
          chart: {
            type: 'line',
            height: 350,
          },
          stroke: {
            curve: 'stepline',
          },
          dataLabels: {
            enabled: false,
          },
          title: {
            text: 'Thermostat Setpoint',
            align: 'left',
          },
          subtitle: {
            text: "curve: 'stepline' holds each value until the next point",
            align: 'left',
          },
          xaxis: {
            categories: [
              '00:00',
              '02:00',
              '04:00',
              '06:00',
              '08:00',
              '10:00',
              '12:00',
              '14:00',
              '16:00',
              '18:00',
              '20:00',
            ],
          },
          yaxis: {
            labels: {
              formatter: (val) => {
                return val + '°C'
              },
            },
          },
          markers: {
            hover: {
              sizeOffset: 4,
            },
          },
        };
  ngAfterViewInit() {
    (window as any).ApexCharts.setLicense('APEX-eyJleHBpcnlEYXRlIjoiMjEyNi0wNy0wNCIsImlzc3VlRGF0ZSI6IjIwMjYtMDctMjgiLCJwbGFuIjoicHJlbWl1bSIsImRvbWFpbnMiOlsiYXBleGNoYXJ0cy5jb20iLCIxMjcuMC4wLjEiLCJsb2NhbGhvc3QiXSwic2lnIjoieVBmb1VCc0Z3TU9ZdUEyaEZkR0I2Y1FtZ0JITUtXcVdJSjB2NVRESXRZbFR3eDJMUmh6R2x0RUc3VXJ4X0s3b25ZMWRZb2Z2VGItN01ydFYyNDVyOWcifQ==');
  }

  ngOnDestroy() {
    // no cleanup needed
  }
}
Stepline Chart - Angular Line Charts | ApexCharts.js | ApexCharts.js