<form class=" was-validated" method="POST" class="needs-validation" novalidate>

<div class="md-form input-group">

​

​

        <div class="form-check form-check-inline">

            <input type="radio" class="form-check-input" id="age1" name="age" value="child"

                    required>

            <label class="form-check-label" for="age1">Dziecko</label>

        </div>

​

        <div class="form-check form-check-inline">

            <input type="radio" class="form-check-input" id="age2" name="age"

                   value="adult" required>

            <label class="form-check-label" for="age2">Dorosły</label>

​

        </div>

            <div class="invalid-feedback ">

                Error

            </div>

  </div>

  <div class="md-form input-group">

      <div class="form-check form-check-inline">

            <input type="radio" class="form-check-input" id="age1" name="age" value="child"

                    required>

            <label class="form-check-label" for="age1">Dziecko</label>

        <div class="invalid-feedback ">

                Error

            </div>

        </div>

​

        <div class="form-check form-check-inline">

            <input type="radio" class="form-check-input" id="age2" name="age"

                   value="adult" required>

            <label class="form-check-label" for="age2">Dorosły</label>

​

        </div>

    </div>

</form>