gistfile1.txt

    <inbound>
        <set-header name="x-rejsekort-jwt-clientid" exists-action="append">
            <value>@{
                string clientID = string.Empty;
                string token = context.Request.Headers.GetValueOrDefault("Authorization", "");
                
                
                if (token?.Length > 0)
                {
                    string[] tokenParts = token.Split(' ');
                    
                    if (tokenParts?.Length == 2 && tokenParts[0].Equals("bearer", StringComparison.InvariantCultureIgnoreCase))
                    {
                        Jwt jwt;
                        if (tokenParts[1].TryParseJwt(out jwt))
                        {
                            clientID = jwt.Claims.GetValueOrDefault("client_id", string.Empty);
                        }
                    }
                }
                return clientID;
            }</value>
        </set-header>
        <base />
    </inbound>