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: 'Gateway 1',
              data: [
                {
                  x: 'Dec 23 2024',
                  y: null,
                },
                {
                  x: 'Dec 24 2024',
                  y: 44,
                },
                {
                  x: 'Dec 25 2024',
                  y: 31,
                },
                {
                  x: 'Dec 26 2024',
                  y: 38,
                },
                {
                  x: 'Dec 27 2024',
                  y: null,
                },
                {
                  x: 'Dec 28 2024',
                  y: 32,
                },
                {
                  x: 'Dec 29 2024',
                  y: 55,
                },
                {
                  x: 'Dec 30 2024',
                  y: 51,
                },
                {
                  x: 'Dec 31 2024',
                  y: 67,
                },
                {
                  x: 'Jan 01 2025',
                  y: 22,
                },
                {
                  x: 'Jan 02 2025',
                  y: 34,
                },
                {
                  x: 'Jan 03 2025',
                  y: null,
                },
                {
                  x: 'Jan 04 2025',
                  y: null,
                },
                {
                  x: 'Jan 05 2025',
                  y: 11,
                },
                {
                  x: 'Jan 06 2025',
                  y: 4,
                },
                {
                  x: 'Jan 07 2025',
                  y: 15,
                },
                {
                  x: 'Jan 08 2025',
                  y: null,
                },
                {
                  x: 'Jan 09 2025',
                  y: 9,
                },
                {
                  x: 'Jan 10 2025',
                  y: 34,
                },
                {
                  x: 'Jan 11 2025',
                  y: null,
                },
                {
                  x: 'Jan 12 2025',
                  y: null,
                },
                {
                  x: 'Jan 13 2025',
                  y: 13,
                },
                {
                  x: 'Jan 14 2025',
                  y: null,
                },
              ],
            },
          ],
          chart: {
            type: 'area',
            height: 350,
            animations: {
              enabled: false,
            },
            zoom: {
              enabled: false,
            },
          },
          dataLabels: {
            enabled: false,
          },
          stroke: {
            curve: 'straight',
          },
          fill: {
            type: 'gradient',
            gradient: {
              opacityFrom: 0.5,
              opacityTo: 0.1,
            },
          },
          markers: {
            size: 5,
            hover: {
              size: 9,
            },
          },
          title: {
            text: 'Sensor Uptime',
          },
          subtitle: {
            text: 'Dropped readings (null values) leave gaps in the area',
          },
          tooltip: {
            intersect: true,
            shared: false,
          },
          xaxis: {
            type: 'datetime',
          },
          yaxis: {
            title: {
              text: 'Throughput (Mbps)',
            },
          },
        };
  ngAfterViewInit() {
    (window as any).ApexCharts.setLicense('APEX-eyJpc3N1ZURhdGUiOiIyMDI2LTA0LTE2IiwiZXhwaXJ5RGF0ZSI6IjIwNTItMDQtMTciLCJwbGFuIjoiZW50ZXJwcmlzZSIsImRvbWFpbnMiOlsiYXBleGNoYXJ0cy5jb20iLCIxMjcuMC4wLjEiXX0=');
  }

  ngOnDestroy() {
    // no cleanup needed
  }
}
Missing / Null Values - Angular Area Charts | ApexCharts.js | ApexCharts.js