string domain = $"https://{ConfigurationManager.AppSettings["Auth0:Domain"]}/";
string customDomain = $"https://{ConfigurationManager.AppSettings["Auth0:CustomDomain"]}/";
string audience = ConfigurationManager.AppSettings["Auth0:Audience"];
OpenIdConnectSigningKeyResolver keyResolver = new OpenIdConnectSigningKeyResolver(domain);

app.UseJwtBearerAuthentication(
	new JwtBearerAuthenticationOptions
	{
		AuthenticationMode = AuthenticationMode.Active,
		TokenValidationParameters = new TokenValidationParameters
		{
			ValidAudience = audience,
			ValidIssuers = new[] { domain, customDomain },
			IssuerSigningKeyResolver = (token, securityToken, identifier, parameters) => keyResolver.GetSigningKey(identifier),
			RoleClaimType = "https://my-custom-claim/role"
		}
	});