Issue with cast_assoc for nested has_many assoc

please i would like to understand how to implement cast_assoc form for has many relationship using inputs_for for the nested relationship but currently only working for has_one and not implementing for has_many relatiosnhip, when it comes to has many only the main field showing not the associated field:

Screenshot (69)1200×675 38.9 KB

  <%= form_for @payment_changeset, "#", [phx_submit: :create_payment, phx_change: :validate_payment_entry, phx_target: @myself, id: "capture_account_info"], fn f -> %>
          <div class="border border-gray-300 rounded-lg p-6 bg-white shadow-md">
            <div class="manual-entry-css">
              <div class="flex md:flex-row flex-col items-center justify-between gap-4">
                <%= inputs_for f, :beneficiaries, fn b_changeset -> %>
                  <div class="py-3">
                    <%= select(
                      b_changeset,
                      :bank_id,
                      Enum.map(@bank_names, &{&1.bank_name, &1.id}),
                      required: true,
                      class: "focus:outline-0 px-4 py-2 rounded-l-md w-full border form-control",
                      phx_update: :ignore
                    ) %>
                    <%= hidden_input(b_changeset, :bank_location, value: "local") %>
                  </div>

                  <div class="py-3">
                    <%= text_input(b_changeset, :account_number,
                      required: true,
                      class: "w-full form-control",
                      placeholder: " Account Number"
                    ) %>
                    <p class="block ">
                      <%= error_tag(b_changeset, :account_number) %>
                    </p>
                  </div>
                <% end %>
                <div class="py-3">
                  <%= text_input(
                    f,
                    :balance,
                    class: "w-full form-control",
                    placeholder: "Amount",
                    required: true
                  ) %>
                </div>
              </div>
            </div>
            <div class="flex items-end justify-end lg:mt-2 mt-4">
              <button phx-target={@myself} type="submit" class="btn-primary rounded-sm">
                Add
              </button>
            </div>
          </div>
        <% end %>
      </div>
    <% end %>

please i need help with fixing this problem