google-api-go-client SiteVerification API 503 Error

[Rayane BELLAZAAR]

Hi everyone, 

I'm trying to use this api SiteVerification API by using the official Golang SDK and I have a weird error return by google API when I'm trying to use the insert call: googleapi: Error 503: An unexpected error occurred. Please try your request again., backendError.

Can someone help me to understand what's going on ? because I've met all the requirements from the documentation but for a domain (not a site). So, in my code I do the following steps:

1. Authentication to the google API by using a service account token.

2. Call getToken method to retrieve the verification token for my domain (DNS TXT)

3. Insert the TXT record in the DNS zone (I did this manually for now)

4. Call the insert method to ask google to verify my domain.

Here you can find the code: https://gist.github.com/rayanebel/7629ee7c82b2f2c1b10e8469949f37d0

Thanks you for your help