Sending post request with headers

I had fine-working rule with sending a http post request with content, but now it seems that I also need to send a header with authoriation.

In docs ( I found that you can send header also:

sendHttpPutRequest(String url, String contentType, String content, Map<String, String> headers, int timeout)

and an example:

val headers = newHashMap("Cache-control" -> "no-cache")
val output = sendHttpGetRequest("", headers, 1000)

Unfortunately, when I’m trying to send it, got errors. My rule:

    var url_light="some url"
	var content
	var headers = newHashMap("Integration" -> "true", "Authorization" -> "Bearer xxx")
	content='{ "some content": "value", "some content":"value2"}'
	sendHttpPostRequest(url_light, "application/json", content, headers, 1000)

And the error from logs:

2020-03-12 07:12:00.082 [ERROR] [ntime.internal.engine.ExecuteRuleJob] - Error during the execution of rule 'Status send': An error occurred during the script execution: Could not invoke method: org.eclipse.smarthome.model.script.actions.HTTP.sendHttpPostRequest(java.lang.String,java.lang.String,java.lang.String,int) on instance: null

It seems like docs are false or I’m doing something wrong. In addition I can say, that without headers all was working fine. Any advice?

The docs reference a 3.0 feature.

There’s some additional info here.