API Connector - Google Calendar Freebusy API Error

Hi,

can anyone pls help me identify the issue with API call to FreeBusy? (Freebusy  |  Google Calendar  |  Google for Developers).

Here’s parameters I am putting in:

But getting error saying:
undefined error: this header name is not correct undefined

I tried adding headers [Access: application/json] as well as Authorization: Bearer [token[, but no results.

Before getting to freebusy, I have made API calls to get access and refresh tokens.
Do need to have another API call before getting to Freebusy?

Thank you

this is solved- getting response. The way I understand, if wrong call has been made, it’s best to reproduce the API call and try again from scratch.
Plus, URL has been missing ?key=[key], and in header I had to add the API key.

However, response gives the following:

{
“kind”: “calendar#freeBusy”,
“timeMin”: “2021-12-07T19:23:31.000Z”,
“timeMax”: “2022-02-07T19:23:31.000Z”,
“calendars”: {
“primary”: {
“errors”: [
{
“domain”: “global”,
“reason”: “internalError”
}
],
“busy”:
}
}
}

Internal error is outputted. Does anyone know how can this be tackled?

edit: found out this is because primary calendar did not give persmission for sharing.