In your Google document, click on Share in the upper right corner of the screen.

Set your desired access options, then click on Copy.

Embedding Google documents with restricted access
Viewing Google documents with organization or restricted access requires an authorized Google account and consequently, the ability to log into such account.
However, Google’s support to external authentication is currently limited.
If a user tries to view a restricted document through an embedder app and they’re NOT logged into any Google account, Google’s login screen won’t show up and instead a generic error will be displayed.

Fortunately, you can still get around this issue by logging in another way, depending on your case.
In either case, please note that:
CASE A: You’re using Jira/Confluence or monday.com in your browser
open a separate tab and access any Google product
log into your Google account
go back to Jira/Confluence or monday.com and refresh the page
CASE B: You’re using the monday.com desktop client
Temporarily disable the restriction OR copy the link of any unrestricted Google file.
It has to be compatible with the embedder you’re using.
Example: Google Sheets Embedder 👉 use a Google Sheets unrestricted link
Embed the link or refresh the page if you’re not changing link
Click on Access and log into your Google account. You will be redirected to the external service (e.g. Google Sheets).
Go back to the page where you embedded the document (in either Jira/Confluence or monday.com)
You can now enable the restriction again or swap back to the file you originally intended to embed