btcpayserver/BTCPayServer/Views/UIWallets/WalletSendVault.cshtml

@model WalletSendVaultModel
@{
    var walletId = Context.GetRouteValue("walletId").ToString();
    Layout = "_LayoutWizard";
    ViewData.SetActivePage(WalletsNavPages.Send, "Sign the transaction", walletId);
	var returnUrl = this.Context.Request.Query["returnUrl"].FirstOrDefault();
}

@section Navbar {
	@if (returnUrl is string)
	{
    <a href="@returnUrl" id="GoBack">
        <vc:icon symbol="back" />
    </a>
    <a href="@returnUrl" class="cancel">
        <vc:icon symbol="close" />
    </a>
	}
}

<header class="text-center">
    <h1>@ViewData["Title"]</h1>
    <p class="lead text-secondary mt-3">Using BTCPay Server Vault</p>
</header>

<div id="walletAlert" class="alert alert-danger alert-dismissible my-4" style="display:none;" role="alert">
    <button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close">
        <vc:icon symbol="close" />
    </button>
    <span id="alertMessage"></span>
</div>

<div id="body" class="my-4">
    <form id="broadcastForm" asp-action="WalletSendVault" asp-route-walletId="@walletId" asp-route-returnUrl="@returnUrl" method="post" style="display:none;">
        <input type="hidden" id="WalletId" asp-for="WalletId" />
        <input type="hidden" asp-for="WebsocketPath" />
        <partial name="SigningContext" for="SigningContext" />
    </form>
    <div id="vaultPlaceholder"></div>
    <button id="vault-retry" class="btn btn-primary" style="display:none;" type="button">Retry</button>
    <button id="vault-confirm" class="btn btn-primary" style="display:none;"></button>
</div>

<partial name="VaultElements" />

@section PageFootContent
{
    <script src="~/js/vaultbridge.js" type="text/javascript" defer="defer" asp-append-version="true"></script>
    <script src="~/js/vaultbridge.ui.js" type="text/javascript" defer="defer" asp-append-version="true"></script>
    <script>
        async function askSign() {
            var websocketPath = $("#WebsocketPath").val();
            var loc = window.location, ws_uri;
            if (loc.protocol === "https:") {
                ws_uri = "wss:";
            } else {
                ws_uri = "ws:";
            }
            ws_uri += "//" + loc.host;
            ws_uri += websocketPath;
            var html = $("#VaultConnection").html();
            $("#vaultPlaceholder").html(html);
            var vaultUI = new vaultui.VaultBridgeUI(ws_uri);
            
            while (!await vaultUI.askForDevice() || !await vaultUI.askSignPSBT({
                walletId: $("#WalletId").val(),
                psbt: $("#SigningContext_PSBT").val()
            })) {
            }
            $("#SigningContext_PSBT").val(vaultUI.psbt);
            $("#broadcastForm").submit();
        }
        document.addEventListener("DOMContentLoaded", function () {
            askSign();
        });
    </script>
}