custom data connector with URL as parameter for a web api

I am building the custom data connector where I have a situation to take URL as a parameter. So basically if the user finds our connectors from the market place the first step will be inputing the domain name like below 

 Here is my M Language Code: 

[DataSource.Kind="TConnectorPOC", Publish="TConnectorPOC.Publish"]
shared TConnectorPOC.Contents = (optional message as text) =>
    let
      
        source=Json.Document(Web.Contents(basicURL & endpoint )),
      #"Converted to Table" = Table.FromList(source, Splitter.SplitByNothing(), null, null, ExtraValues.Error),
       #"Expanded Column1" = Table.ExpandRecordColumn(#"Converted to Table", "Column1", {"projectId", "parentQuoteId", "projectGroupId","projectGroupCode", "projectGroupName", "code", "name", "description", "status", "customerId","customerContactId", "templateId"})
    in
         #"Expanded Column1";

Basically my basicURL should prompt the first image if the users open our connector. Kindly help. thanks