// shared.module.ts

    .....
    import { NativeScriptFormsModule } from "nativescript-angular/forms";

    @NgModule({
        imports: [
            .....
            NativeScriptFormsModule,
            .....
        ],
        declarations: [
            .....
        ],
        exports: [
            .....
            NativeScriptFormsModule,
            .....
        ]
    })
    export class SharedModule { }

// signon.module.ts

    .....
    import { SharedModule } from "../shared/shared.module";