How to do I locate a Google SpreadSheet ID?

Found this deep inside the Apps Script API reference.

A spreadsheet ID can be extracted from its URL. For example, the spreadsheet ID in the URL https://docs.google.com/spreadsheets/d/abc1234567/edit#gid=0 is "abc1234567".

https://developers.google.com/sheets/api/guides/concepts

states that:

Every API method requires a spreadsheetId parameter which is used to identify which spreadsheet is to be accessed or altered. This ID is the value between the "/d/" and the "/edit" in the URL of your spreadsheet. For example, consider the following URL that references a Google Sheets spreadsheet:

https://docs.google.com/spreadsheets/d/1qpyC0XzvTcKT6EISywvqESX3A0MwQoFDE8p-Bll4hps/edit#gid=0

The ID of this spreadsheet is 1qpyC0XzvTcKT6EISywvqESX3A0MwQoFDE8p-Bll4hps.

So I just pulled up my spreadsheet and looked at the URL to find my ID.

Hope this helps!