How to give POST in a fetch in ReactJS?

I have an API in nodeJS and a SPA in ReactJ for registration of courses (only with the title of the same course, in a mongo bank), I have already done a function, with fetch, to search the registered courses and is working, but I do not know how to save my courses in the bank.

<input id='name' name='name' placeholder='Título do Curso' type='text' required />
                        <div className='panel-footer text-center'>
                            <button className='btn btn-lg'>Cadastrar</button>
                        </div>