Could not find a declaration file for module 'buffer-layout': @solana/spl-token

I'm trying to work with @solana/spl-token lib for transferring tokens but when I tried to install and run ng serve (using Angular 11). I'm getting the following error:

Could not find a declaration file for module 'buffer-layout'. './node_modules/buffer-layout/lib/Layout.js' implicitly has an 'any' type.

Try `npm install @types/buffer-layout` if it exists or add a new declaration (.d.ts) file containing `declare module 'buffer-layout';`

   import {Layout} from 'buffer-layout';

I've tried to include

declare module 'buffer-layout';

in src/index.d.ts file but it didn't work.

I also get

 Namespace '"./node_modules/@angular/core/core"' has no exported member 'ɵɵFactoryDeclaration'.
    
    7     static ɵfac: i0.ɵɵFactoryDeclaration<ToastContainerDirective, never>;

Cannot use namespace 'Layout' as a type.
    
       export const MintLayout: Layout;

Would be great if someone can help out here.

Thanks in advance!