MrSmoke

public async Task<IActionResult> DoChallenge(string returnUrl)
{
    var context = await _interaction.GetAuthorizationContextAsync(returnUrl);

    var acrTenantValue = context.AcrValues.First(v => v.StartsWith("tenantId:"));
    var tentantId = acrTenantValue.Split(':')[1];

    // start challenge and roundtrip the return URL and
    var props = new AuthenticationProperties
    {