JSFiddle - React, Tailwind, and code Playground

HTML

<form action="" id="myForm">
  <input name="name">
  <input type="submit">
</form>

<pre id="out"></pre>

JavaScript

const users = {
  'Семен':  {age: 25, height: 180, weight: 80},
  'Игорь':  {age: 27, height: 165, weight: 70},
};

myForm.addEventListener('submit', evt => {
  evt.preventDefault();
  
  const name = myForm.name.value;
  const user = users[name] || null;

  out.textContent = JSON.stringify(user, null, 4);
});