@bi8/am-dyn-form/app/modules/am-dyn-form/dyn-form-array.d.ts

ng update @angular/cli yarn add @angular/cli

import { AbstractControl, FormArray } from "@angular/forms";
export declare class DynFormArray extends FormArray {
    key: string;
    dir: string;
    config: any;
    constructor(options: {
        key?: string;
        dir?: string;
    }, controls: AbstractControl[]);
    add(values?: any): void;
}