aws step function converting special characters to UTF-8 in URL (not able to pass correct URL with query parameter to API gateway)

I am using api-gateway invoke task in step-function but not able to use query parameters in PATH

here is my step function defination

{
  "Type": "Task",
  "Resource": "arn:aws:states:::apigateway:invoke",
  "Parameters": {
    "ApiEndpoint": "endpoint",
    "AuthType": "IAM_ROLE",
    "Headers": {
      "Content-Type": [
        "application/json"
      ]
    },
    "Method": "GET",
    "Path": "path?a=1",
    "RequestBody.$": "$"
  },
  "End": true
}

when I use a=1 in query parameter it converts it to path%3F%7B%7D like format and give error.

I also know about queryparameter in apigateway invoke task but the problem is I have input like a=1 if I pass this to query parameter it will also fail. as query paramter expect something like this

 "QueryParameters": {
      "a": [
        "1"
      ]
    }

Any idea how to solve this problem within step function?

I have solved problem by passing query parameter from api-gateway separately as key and value

{
    "key": "a",
    "value": "1"
}

then used Intrinsic functions in state machine to handle in QueryParameter like this:

"QueryParameters.$": "States.StringToJson(States.Format(' \\{  \"{}\":[\"{}\"]  \\}', $.key , $.value))"