import 'flatpickr/dist/flatpickr.css'; // you may need to adjust the css import depending on your build tool
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { FlatpickrModule, FLATPICKR } from 'angularx-flatpickr';
import * as flatpickr from 'flatpickr';

export function flatpickrFactory() {
  return flatpickr;
}

@NgModule({
  imports: [
    FormsModule,
    FlatpickrModule.forRoot({
      provide: FLATPICKR,
      useFactory: flatpickrFactory
    })
  ]
})
export class MyModule {}

import { Component } from '@angular/core';

@Component({
  template: `
    <input 
      type="text" 
      mwlFlatpickr 
      [(ngModel)]="selectedDate" 
      [altInput]="true" 
      [convertModelValue]="true">
  `
})
export class MyComponent {}