Update existing form via API


I try to use KoboForms API to make changes in existing form.
I would like to create/update a form based on data from my application.
The problem is that actually only name of form is updated and never survey. No matter if it’s deployed or not.

“content”: {
“survey”: [
“type”: “text”,
“name”: “test project - NA”

this is example content from Headers that goes when I update form via UI.
Sending the same request to any new form (empty with random name) changes only name, does not add any question. I trie also with deleted $kuid and start/end objects.
Those are options that I send to node.js request promise call:

const options = {
        method: 'PATCH',
        uri: `${this.config.koboForms.formsUrl}/assets/${uid}/`,
        headers: {
          authorization: `Token ${this.config.koboForms.token}`,
          accept: 'application/json'
        form: querystring.stringify(form)

Does anyone has any hint? Does anyone had similar problem?
Greetings and thanks!