What is the full format of a /v1/bars request for multiple stocks

I am using C# in VS2019. I tried the C# SDK but kept running into ‘not authorized’ programs. So I started writing requests myself just using the RestClient() code. That at least gets me the simpler things like accounts, etc.

I am not trying to gets 1 minutes data for multiple stocks to drive my algorithm but do not see how to format up the request. I only have a paper trading account at this time and the documentation says connect to “https://data.alpaca.markets/v1/bars” for data. The docs show calls to .GetBarsetAsync() and I would like to know how to format that data as it is not clear in the Docs or trying to read someone else code.

I have tried:
string url = Program.APCA_API_BASE + “/bars”;
url += “/AAPL”;
url += “/1min/10”;

        var client = new RestClient(url);
        client.Timeout = -1;
        var request = new RestRequest(Method.GET);
        request.AddHeader("APCA-API-KEY-ID", Program.APCA_API_KEY_ID);
        request.AddHeader("APCA-API-SECRET-KEY", Program.APCA_API_SECRET_KEY);
        IRestResponse response = client.Execute(request);
        Console.WriteLine(response.Content);

This returns ‘endpoint not found’

I am hoping that someone can enlighten me about what comes after the https://data.alpaca.markets/v1\bars … like
https://data.alpaca.markets/v1/bars?symbols:AAPL&timestamp:1min&lim:10