Bir kodu kopyalamak istediğinizda sayfanın kaynağına girip tüm css ve javascript kodlarını kodunuza eklersiniz.
Butonların bootstrap ile alakası yok, sayfa kendi custom kodlarını kullanarak yapmış.
Şu kodları css kodunun sonuna ekle butonlar da düzelir.

/* End basic CSS override */
.profile {
  display: flex;
  align-items: center;
  flex-direction: column;
  padding: 3rem;
  width: 90%;
  max-width: 300px;
  background-color: #1b2028;
  border-radius: 16px;
  position: relative;
  border: 3px solid transparent;
  background-clip: padding-box;
  text-align: center;
  color: #f1f3f3;
  background-image: linear-gradient(135deg, rgba(117, 46, 124, 0.35), rgba(115, 74, 88, 0.1) 15%, #1b2028 20%, #1b2028 100%);
}
.profile:after {
  content: "";
  display: block;
  top: -3px;
  left: -3px;
  bottom: -3px;
  right: -3px;
  z-index: -1;
  position: absolute;
  border-radius: 16px;
  background-image: linear-gradient(135deg, #752e7c, #734a58 20%, #1b2028 30%, #2c333e 100%);
}

.profile-image {
  border-radius: 50%;
  overflow: hidden;
  width: 175px;
  height: 175px;
  position: relative;
}
.profile-image img {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 100%;
}

.profile-username {
  font-size: 1.5rem;
  font-weight: 600;
  margin-top: 1.5rem;
}

.profile-user-handle {
  color: #7d8396;
}

.profile-actions {
  margin-top: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
}
.profile-actions > * {
  margin: 0 0.25rem;
}

.btn {
  border: 0;
  background-color: transparent;
  padding: 0;
  height: 46px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  line-height: 1;
  transition: 0.15s ease;
}
.btn--primary {
  border-radius: 99em;
  background-color: #3772ff;
  background-image: linear-gradient(135deg, #5587ff, #3772ff);
  color: #fff;
  padding: 0 1.375em;
}
.btn--primary:hover, .btn--primary:focus {
  background-size: 150%;
}
.btn--icon {
  height: 46px;
  width: 46px;
  border-radius: 50%;
  border: 3px solid #343945;
  color: #7d8396;
}
.btn--icon i {
  font-size: 1.25em;
}
.btn--icon:hover, .btn--icon:focus {
  border-color: #7d8396;
}

.profile-links {
  margin-top: 3.5rem;
}

.link {
  text-decoration: none;
  color: #7d8396;
  margin-left: 0.375rem;
  margin-right: 0.375rem;
}
.link i {
  font-size: 1.25em;
}