Is this considered a bad practice, using a hard dependency inside a function. Something like ServiceLocator anti pattern in OOP ?

Application.fs

// And here is how both of them are composed in a higher level module so I can pass in another function without hard dependency for testing
let keys = [| "SOclient_id"; "SOscope"; "SOredirect_uri"|]
let queryParameters = readConfigApi keys readConfigurationValue

Infrastructure.fs

// tried to isolate a hard dependency in different function
let readConfigurationValue keyValue =
        (keyValue, RocketCvRuntimeContext.Instance.ConfigurationManager.GetConfigurationValue(keyValue))
        
// here is the high level function using indirectly the first one
let readConfigApi keys configValueReader =
        keys |> Seq.map (fun e ->
                            e |> configValueReader
                            )
             |> Map.ofSeq

And if you have some tips how a functional programer would write this it would be great

You don't need the lambda for a start:

let readConfigApi keys configValueReader =
        keys |> Seq.map configValueReader |> Map.ofSeq

Thanks for the tips.

Just wanted to say that this dependency is coming from a C# part :
RocketCvRuntimeContext.Instance.ConfigurationManager.GetConfigurationValue(keyValue)

Is there any recommendation on how to deal with such a code ? When you have to use some pieces of the code made for different purposes ?

You could add a function that had the same signature to the readConfigurationValue function and pass in the RocketCvRuntimeContext.Instance.ConfigurationManager.GetConfigurationValue function in. Then you could abstract to another configuration provider.