I have installed the bootstrap through yarn :

yarn Add Bootstrap@4.2.1

And include it in index.js file:

import "bootstrap/dist/css/bootstrap.css"

here I uses the collapse component through snipped:

             <div>
                <p>
                    <a className="btn btn-primary" data-toggle="collapse" href="#collapseExample" role="button" aria-expanded="false" aria-controls="collapseExample">
                        a
                    </a>
                    <button className="btn btn-primary" type="button" data-toggle="collapse" data-target="#collapseExample" aria-expanded="false" aria-controls="collapseExample">
                        b
                    </button>
                </p>
                <div className="collapse" id="collapseExample">
                    <div className="card card-body">
                        Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident.
                    </div>
                </div>
            </div>

but when I clicked a or b buttons nothing happens.

how can I solve it?