server/src/Api/Controllers/MiscController.cs

using Microsoft.AspNetCore.Mvc;
using Bit.Core.Models.Api;
using System.Threading.Tasks;
using Bit.Core.Utilities;
using Microsoft.AspNetCore.Authorization;
using Bit.Core.Settings;
using Stripe;
using System.Linq;
using System.Collections.Generic;

namespace Bit.Api.Controllers
{
    public class MiscController : Controller
    {
        private readonly BitPayClient _bitPayClient;
        private readonly GlobalSettings _globalSettings;

        public MiscController(
            BitPayClient bitPayClient,
            GlobalSettings globalSettings)
        {
            _bitPayClient = bitPayClient;
            _globalSettings = globalSettings;
        }

        [Authorize("Application")]
        [HttpPost("~/bitpay-invoice")]
        [SelfHosted(NotSelfHostedOnly = true)]
        public async Task<string> PostBitPayInvoice([FromBody]BitPayInvoiceRequestModel model)
        {
            var invoice = await _bitPayClient.CreateInvoiceAsync(model.ToBitpayInvoice(_globalSettings));
            return invoice.Url;
        }

        [Authorize("Application")]
        [HttpPost("~/setup-payment")]
        [SelfHosted(NotSelfHostedOnly = true)]
        public async Task<string> PostSetupPayment()
        {
            var options = new SetupIntentCreateOptions
            {
                Usage = "off_session"
            };
            var service = new SetupIntentService();
            var setupIntent = await service.CreateAsync(options);
            return setupIntent.ClientSecret;
        }
    }
}