Static method requires that 'NSDictionary' conform to 'Encodable' - json

Question

I am trying to make a http request function for calling an API I want to use. I keep getting the error that NSDictionary needs to conform to Encodable but in the initializations before the call Ive already made it encodable.
What am I doing wrong?
Error message
Static method 'apiRequest(method:params:url:authToken:)' requires that 'NSDictionary' conform to 'Encodable'
Below is the initialization for the API request parameters.
private struct APIBody<CallParams: Encodable>: Encodable {
var method: String
var params: CallParams
var jsonrpc = "2.0"
var id = Int64(Date().timeIntervalSince1970)
}
private static let bodyEncoder: JSONEncoder = {
let e = JSONEncoder()
e.keyEncodingStrategy = .convertToSnakeCase
return e
}()
Below is the initialization for the API request to be sent.
private static func apiRequest<Params: Encodable>(
method: String,
params: Params,
url: URL,
authToken: String?
) throws -> URLRequest {
let body = APIBody(method: method, params: params)
var req = URLRequest(url: url)
req.httpMethod = "POST"
do {
req.httpBody = try bodyEncoder.encode(body)
} catch let e {
assertionFailure("API encoding error: \(e)")
throw e
}
req.addValue("application/json", forHTTPHeaderField: "Content-Type")
req.addValue("application/json", forHTTPHeaderField: "Accept")
if let authToken = authToken, !authToken.isBlank {
req.addValue(authToken, forHTTPHeaderField: "X-Lbry-Auth-Token")
}
return req
}
Below is the final call to the API where I get the error.
static func apiCall(
method: String,
params: [String: Any],
connectionString: String,
authToken: String? = nil,
completion: #escaping ([String: Any]?, Error?) -> Void
) {
let req: URLRequest
do {
req = try apiRequest( //<-- Error throws on this Line *********************
method: method,
params: params as NSDictionary,
url: URL(string: connectionString)!,
authToken: authToken
)
} catch let e {
completion(nil, e)
return
}
let task = URLSession.shared.dataTask(with: req, completionHandler: { data, response, error in
guard let data = data, error == nil else {
// handle error
completion(nil, error)
return
}
do {
Log.verboseJSON.logIfEnabled(.debug, "Response to `\(method)`: \(String(data: data, encoding: .utf8)!)")
let response = try JSONSerialization.jsonObject(with: data, options: []) as? [String: Any]
if response?["result"] != nil {
completion(response, nil)
} else {
if response?["error"] == nil, response?["result"] == nil {
completion(nil, nil)
} else if response?["error"] as? String != nil {
completion(nil, LbryApiResponseError(response?["error"] as! String))
} else if let errorJson = response?["error"] as? [String: Any] {
completion(nil, LbryApiResponseError(errorJson["message"] as! String))
} else {
completion(nil, LbryApiResponseError("unknown api error"))
}
}
} catch {
completion(nil, error)
}
})
task.resume()
}