A few posts before this one in this thread, you’ll see that I recently upgraded from the Nest 1.x binding to the 2.x. To do this I needed to get my access token, productid and productsecret. The access token is the thing you cannot generate anymore. You can easily see the other two in your current next config, but OH hides the access token here (on my openhabian install) /srv/openhab2-userdata/.java/.userPrefs
With these three pieces of data, install the nest binding in PaperUI, click to config, click on advanced options and put these three in. I highly suspect you’ll have an operational Nest 2.x binding on the new system.